I know what you're thinking: Gandalf is from The Lord of the Rings, not Skyrim. But hear me out. Gandalf the White has made his way through space and time and arrived at the Land of the Nords.
As we speak, Gandalf is probably hanging out at Dragonsreach, talking about how he's got more strength in his left pinky than all four Greybeards have in their entire bodies combined. There's a reason he got promoted from Gandalf the Grey - those lads up at the top of High Hrothgar are nothing but pretenders.
Anyway, it turns out that Gandalf is really lovely in Skyrim, as evidenced by a recently published Reddit post. Check out the post below, which includes a video of Gandalf being half-wizard, half-surfer bro.
The caption is magical, isn't it? And not just because it's about a member of the Istari - "There's Galmar Stone-Fist and then there's Gandalf Bro-Fist." That's just irrefutably excellent work, I reckon.
But let's talk about the video itself. First of all, the Dragonborn has a gun for some reason. He kills Talia, even though she says, "I'm on your side." But when he reloads and walks up to Gandalf, Old Greybeard sheathes his sword and just goes, "Fist-bump, bro." After tussles with Balrogs and voyages to Mordor, he knows exactly how to distill a tense situation.
Well, except on occasions like when Bilbo tries to hide the One Ring and Gandalf turns into a scary storm wizard who causes lightning bolts to manifest inside, which is definitely a fire hazard. That was probably the worst way to lower the tension, but you live and you learn.
Anyway, this isn't the first time Gandalf has accidentally wandered into the wrong fantasy world. In fact, you're able to make a pretty decent Gandalf build in Dungeons and Dragons.
I suppose it makes sense. Given that there aren't any new Lord of the Rings books coming out and that Gandalf is technically thousands of years old with even more than that left, it's only natural he's looking for somewhere to fit in. That actually kind of explains why he offers you a fist-bump in Skyrim, too. He probably reckons that's what the cool kids do in Whiterun.