Honestly that's a big part of it. You say something enough with conviction and follow through and it becomes reality.
Despite how I feel about him now I will say this positive thing about Kanye. He was never the most talented emcee nor was he the best beatmaker or producer (despite what his stans say). But the fact that you could hear that his vision outreached his skills on College Dropout for example
is in itself the best thing about it.
You can hear him punching in on that album because his breath control wasn't as good. You can tell it's bloated with too many skits. You can tell some of the features don't work as well as others. Certain parts try to sound bigger than they are. And he had to go out of the box to make certain idea work. For example the flute sound on Jesus Walks is John legend's voice autotuned. The sample for Last Call didn't clear so he had to sample someone else signing the Mr. Rocafella part (also John legend I think).
The album has these imperfections and that's what makes it so dope. His ambition for what he wanted that album to be is so apparent, and eventually his skills improved and he surrounded himself with enough help to make the end product match the vision.
So I've always respected that he had really big goals and aspirations with his albums.