Wizards are very odd kleptomaniacs. Even if this is 4e, and 4e wizards don't need material components to cast spells (off the top of my head, I don't know) they'll still have the ability to produce any number of odd, valueless, seemingly useless objects at the drop of a pointy hat.
Warlocks can't do this. Sorcerers might be able to. Mostly, though, it's something wizards do, because they're weird.
They're not born with power. They want it, but they don't have the sense to do the easy thing and cut a deal with some extradimensional being. (Clerics, I'm looking at you, too.) Whether from principles, morals, or fear, they work for their power.
But then, they're not usual in that, either. They're not like fighters, or rogues; not practice and discipline and skill. They spend all their time reading books. And thinking. And tinkering with the fundamentals of the universe.
All without wearing pants.