Marvel has built their cinematic universe from below the ground up. The heroes we all know and love started their careers in comic books, only bought and collected by the most ardent of geeks. Marvel's beginning in films was not overly promising. Their properties were made into movies that did not garner favorable reviews from critics or from fans. You remember Daredevil? Hulk? Oh, you forgot them? You probably blocked them from your memory. Yeah, there was a time when they weren't cool. You should definitely revisit those movies. That way, the next time you see the Avengers in theaters or catch some Daredevil on Netflix, you can better appreciate the good times we're living in.

The Marvel Cinematic Universe as it stands today is a testament to their perseverance. They have spent years cultivating the talent that goes into making their movies. And for the most part, their work speaks for itself. Not a year goes by that doesn't give us a Marvel super hero film to see in theaters. The quality of story we fans guzzle down greedily should fill us with appreciation for the rise of the super hero in pop culture.

Not every movie carries a shining, golden standard. As with most movies that rely on the premise that certain individuals can do things normal humans can't, there are bound to be inconsistencies and unresolved questions by the end of the film. No matter how popular Marvel movies are, and despite how much better they have been in setting up a cinematic universe than DC, they still have to contend with the occasional plot hole. Here is a list of the 25 most glaring plot holes and unanswered mysteries in the Marvel Cinematic Universe to date.

25 The Universal Language

We don't necessarily go to the movies to read, but occasionally, our reading faculties are called upon when a film includes captions. Captions are used when characters on the screen are not speaking a language the audience is expected to understand, which varies depending on where the film is shown. But what happens when characters speak languages that no one on the planet should know, such as alien languages? In the Marvel universe, English is a known language out and about in space. If you look at Guardians of the Galaxy, despite there being a diverse amount of aliens, they all speak English. Don't know how, don't know why. This is never explained. Maybe they use Babel fish. (Bonus points to any of my readers who know what those are!)

24 Gauntlet Found, Problem Solved

Little Easter Eggs are all fine and dandy to slip into your movies, but if you're building a vast cinematic universe like Marvel, you should be careful about what you tease. In Thor, fans caught a glimpse of the Infinity Gauntlet collecting dust in Odin's vault on Asgard. We know now that the Infinity Gauntlet is the key weapon that big bad Thanos plans to use along with those Infinity Stones. And in one end credits sequence, we saw Thanos menacingly placing the glove upon his hand, in clear ownership of the Gauntlet. So...why are there two Infinity Gauntlets? Thor: Ragnarok attempted to correct this mistake. Hela, the Valkyrie enters Odin's vault and glances at the Infinity Gauntlet, declaring it a fake. Way to go, Marvel. You corrected that little oversight. But then, why did Odin have a fake Infinity Gauntlet in his vault?

23 The Best Medicine

In Iron Man 3, we were introduced to Extremis, an extreme (extreme, Exremis, get it?) form of gene therapy that would enhance healing in humans. Extremis was developed by the bad guys, so of course it ends up being more dangerous than it is helpful. For some reason, if you underwent Extremis therapy, you became super strong and ultra regenerative and developed inexplicable fire powers. An unpleasant side effect of Extremis was that you might become very unstable and explode, Yeah, I have no idea how we went from healing yourself to explosions. In the movie, Pepper Potts is given Extremis under duress and gains some temporary super strength, which she uses to save Tony in the final fight. Because of its unstable nature, Tony creates a cure for her which stabilizes Extremis. Great! Tony now has healing juice that doesn't make you explode. Does he ever use it again? Nope. Guess the many times his super hero friends get hurt is not reason enough to pull out that serum.

22 Follow The Leader

You might not remember The Incredible Hulk aside from the fact that it is not Ang Lee's Hulk, but it left quite the unresolved mystery by the end of the movie. And since The Incredible Hulk is in fact a part of the Marvel Cinematic Universe, that means that this mystery could rear its head in the future. Samuel Sterns aka The Leader made an appearance in The Incredible Hulk before he gained his green skin tone and bulbous forehead. Near the climax, we see Sterns fall victim to his own experimental chemicals. When we saw the skin over his forehead ripple, Hulk fans shivered with excitement at the prospect of the advent of one Hulk's primary villains. We looked forward to seeing The Leader make an appearance in a future Marvel movie. But he never did. So I guess he's out there...somewhere.

21 A Worthless Sacrifice

Captain America is frozen in ice, and then later found by SHIELD. We knew that was going to happen. It's a tale as old as time. So when we piled into theaters to see Captain America: The First Avenger, we knew that our foray into Cap's past was going to end with him turning into an American Cap-sicle. However, his transition to becoming frozen suffered from a lack of sense. With bombs in a plane set to drop in New York, Steve Rogers makes the choice to crash it into the water. He sacrifices himself in order to prevent anyone from being hurt, throttling the plane into a nose dive. Look, if he had control of the plane enough to nose dive, he could have banked the plane around in circles until someone, I don't know, Howard Stark, could have given him instructions to get the plane down safely without hurting anyone. Then Steve and Peggy could have had that darned dance!

20 We Need More Power

Tony Stark spends most of his time in Iron Man 3 out of his suit, and one of the reasons for that is he gets stranded away from home in a suit with little to no power. He then has to hook up his suit to a car battery in order to give it enough juice. It was a nifty opportunity to show Tony going back to his grease monkey roots, but I thought his Iron Man suits were powered by the arc reactor in his chest. These are the same arc reactors that got an upgrade in Iron Man 2. Shouldn't his mini-reactor have powered his suit? And if his reactor suffered a power failure, shouldn't the shrapnel that was inching towards his heart have finally reached their destination and killed Tony?

19 Aren't You Forgetting Something?

You know that sensation you get when you feel as if you've forgotten something important? You've just left your house, you're about to get into the car, when this nagging feeling just pounces on your mind and screams at you that you are forgetting something vitally important to the task at hand. I wonder if Thor got that feeling at the end of the first Avengers movie when he was transporting Loki and the Tesseract back to Asgard. Because he was forgetting one very crucial artifact that he should have taken as well. Loki's scepter had an Infinity Stone, and last we saw of it, it was in the hands of Black Widow as she used it to close the portal above Stark Tower. So the good guys were in possession of the scepter, but it was never given back to Thor to take care of? And in Age of Ultron, we find out that the scepter made its way into the hands of Hydra. How?!

18 Got A Good Thing Going

The Marvel Cinematic Universe has suffered somewhat in the villain department. The most engaging villain they have is Loki, and he is a sometimes-good-guy kind of villain. Obadiah Stane, the main antagonist in Iron Man, was a fairly adequate villain, at least until he started making some very stupid decisions. He starts off secretly trying to get rid of Tony, first paying the Ten Rings to attack his military convoy and then undermining him on the board for Stark Industries. But then it's as if he derails his own plans by blabbing about them to Tony and then jumping into his power armor as soon as some SHIELD agents start investigating. If he had just kept his chill, he could have drawn out the game and slaughtered his opponents in fruitless legal battles.

17 Master Tracker

In Thor: The Dark World, Jane Foster gets some Aether attached to her. Don't know what Aether is? Well, don't worry; I was confused about what exactly it was while I was watching the movie too. It's actually an Infinity Stone in weird powder-liquid form. It has the ability to turn matter into dark matter, and the villain of the Dark World, Malekith, wanted it to bring about eternal darkness in the nine realms, yadda yadda yadda. He can somehow sense the Aether, and he uses it to track Jane after she flees to Asgard with Thor. In an effort to protect Jane, Frigga, Thor's mother, conjures an illusion of Jane in order to trick Malekith. And he falls for it! I thought he could sense Aether! That's how he tracked Jane to Asgard in the first place. Shouldn't he have known that the illusion wasn't the real Jane?

16 Dense Also Means Dumb

The science behind super heroes is not always sound. That's the way it has to be usually. Super abilities don't exist in real life (that we've seen so far), so the scientific background for them tends to be...unrealistic. In Marvel's Ant-Man, Hank Pym creates Pym Particles, which is what is behind the idea of shrinking down to the size of an ant. He described the way this worked as decreasing the spaces between atoms, thereby shrinking solid matter. I don't know overly much about the science of atoms, but if you decreases the spaces between atoms instead of atoms themselves, wouldn't that just make the object you're trying to shrink more dense? Density is the measurement of mass per volume, so with atoms closer together, that's more mass per volume, which is an increase in density. So Ant-Man would just be...denser?

15 Everlasting Battery Life

When Peter Quill was taken from Earth immediately after his mother died, he had no time to pack necessities. Then again, what would you pack to take with you out into the galaxy? One of the only things Peter took with him was his Walkman and his favorite Awesome Mix Tape. He takes good care of that thing as he goes on his adventures as Star Lord in Guardians of the Galaxy, but Walkmans don't last forever. Plus, they run on batteries. Where in the galaxy do they make AA batteries? How could Peter have replaced them? Did he manage to find appropriate space battery substitutes? This mystery is never explored (rightly so, because the imminent destruction of the galaxy is more important than where Peter gets his Walkman some batteries), but maybe it will be addressed eventually.

14 Let's Have A Party

Iron Man 3 was frustrating to me on various levels (don't get me started on the "Mandarin"), and one of the reasons was that there were so many inconsistencies. There were so many moments where I questioned why characters would do one thing in certain circumstances, and then change their tactics in an unexplained manner later on. One of the things that irked me the most was when Iron Man called up the House Party Protocol to help him out in his fight against Aldrich Killian and his forces. Dozens of his Iron Man suits fly up from out of his house and help Tony save the day. Then afterwards, Tony blows them all up to show his devotion to Pepper. My question was this: why didn't he call his House Party way earlier than this?! There were multiple times when Tony was scrambling along without a suit and in dire need of assistance, and he didn't think to call the House Party, or even just a small Get-Together, to help him.

13 Always Angry

Okay, confession time. This is probably the one plot hole I adore in The Avengers. It led to such an awesome moment. When a giant Chitauri space worm glided down to attack the Avengers, small Bruce Banner walks out to meet it. Captain America urges him to get angry so that he could Hulk out and face the space worm. Bruce turns around and almost nonchalantly says that his secret is that he's always angry. Then he turns back to face his foe and just transforms into Hulk. It was a phenomenal moment, but it's centered on a bit of a plot hole. Hulk is the Hulk because he loses control; it's an integral part of what makes his character unique. He never really chooses to become the Hulk. He loses control of his temper and changes into a hulking green monster. This moment in The Avengers makes no sense knowing what we know about the Hulk. But it was a totally cool moment anyways.

12 Spinal Injuries

When Ivan Vanko attacks Tony at the Monaco Race Track, he displays his construction of an arc reactor just like Tony's and uses it to power these whips that he has attached to his arms with metal bracers. His whip slices through race cars as they speed past him, and he looks to be a formidable opponent. Tony, without a suit, is powerless in comparison. Happy Hogan, Tony's personal driver, rushes to deliver an Iron Man briefcase with Pepper in a car, both of them desperate to help their friend. Caught unawares, Vanko gets rammed by Happy's car several times. But, for some reason, he is still able to get back on his feet and fight Tony in an Iron Man suit. Happy hit Vanko at full speed. Vanko should have died, or at least suffered some severe injuries. But Vanko never appears wounded. I don't think Vanko needs his electric whips to be a supervillain. He's already indestructible.

11 Wasted On The Bench

Steve Rogers was part of a pool of candidates for an American super soldier program during World War II. The object of the program was to enhance the best of America's soldiers so that they could have an edge on the field of battle. Sadly, the scientist in charge of the program left no notes or anything that could help someone else follow in his footsteps. When he died, the program was scrapped. That's a mystery in and of itself, because what scientific experiment exists without back-ups? But a bigger mystery is why the US government decided to use Steve Rogers in USO shows instead of in actual combat. Rogers was the first and only candidate of the super soldier program to become super-soldiered. Why did the government decide to waste him away instead of using him? He clearly got the enhancements of a super soldier. Why not utilize his talents?!

10 The Rainbow Bridge Is Falling Down

At the end of Thor, Thor had to destroy the Rainbow Bridge in order to foil Loki's plans. It was a moment of self-sacrifice because destroying that bridge meant that Thor would never be able to see Jane Foster, his love back on Earth, again. It was a defining moment in the hero's life, changing him from a selfish and spoiled boy to a noble man capable of being a leader. Except... well... he manages to get back to Earth anyways. In Avengers, citing some mystical dark arts that Odin performed, Thor makes it back just in time to help the Avengers against the Chitauri menace. I mean, sure, we all wanted Thor to be a part of the Avengers, but how he arrived is just glossed over. So the Bifrost isn't the only way in and out of Asgard? Care to elaborate?

9 We Need A Better Plan

I might need someone to go over Captain America's plan to get captured in Captain America: The First Avenger. Getting caught by the bad guys was the first step. Did he have any guarantee that they would take him alive? Captain America had been earning a reputation as a force to be reckoned with. If I had been a soldier facing against him, I would have panicked and fought for my life, possibly fatally wounding Steve Rogers. The next part of Cap's plan involves him being taken to a certain room by his captors so that his buddies can storm in through the windows and save him. How on Earth could Cap predict what room he would be taken to when he was captured? And how would his friends on the outside know? This plan makes absolutely no sense to me.

8 Death Of A Father Figure

Yondu's sacrifice in Guardians of the Galaxy Vol. 2 was heartbreaking. In his last moments, he showed himself to be the father that Peter had never known he had, and we got to see the soft side to the otherwise tough mercenary. But what I want to know is why couldn't Rocket and the rest of the Guardians have flown to pick up Yondu and Peter more quickly. Yondu was able to fly a safe distance away from the destruction of Ego's planet with just his jetpack. Couldn't the other Guardians have piloted the ship to wait for them in space, far from the surface of the planet? They knew, or at least Rocket did, that Yondu only had one space suit. Yondu's death was meaningful to the story, I'll give the movie that. But did it really need to happen?

7 Trust Issues

As we've gotten more and more movies added to the Marvel Cinematic Universe, we've seen that Thanos is going to be a major villain in Infinity War. We have eagerly watched as the Infinity Stones have made appearances in different films across the universe. Thanos wants those Stones badly, and we're anticipating the moment he has all of them collected in the Infinity Gauntlet. But if gathering Infinity Stones is so important to Thanos, why does he give one to Loki to put in his scepter in The Avengers? Loki, as far as I'm aware, hadn't yet proved himself to Thanos as trustworthy. And he ends up losing! If Thanos was dumb enough to trust Loki with one of his precious Infinity Stones, he definitely won't be a match for all of the Avengers by the time Infinity War rolls around.

6 Hypnotic Resistance

I'm not sure what the rules about mind control are, but I'm fairly certain that it involves one person absolutely controlling the actions of another person. In The Avengers, Loki places Erik Selvig and Hawkeye under some kind of mind control, using them to help him open a portal that will bring Chitauri to Earth. In the film, one of the ways to lose the mind control is to suffer an extreme knock to the head. Selvig, a chief designer of the mechanism that opens the portal, doesn't get his head bashed until the end of the movie. He then reveals that he hid a failsafe in the mechanism that will close the portal. How could he have placed a failsafe in the mechanism if he was being mind-controlled? That's not how mind control works, right?