I feel like I could learn all the facts my classes teach on Wikipedia in a tenth of the time--though procedural knowledge is another matter, of course.

Take it from me (as a dropout-cum-autodidact in a world where personal identity is not ontologically fundamental, I'm fractionally one of your future selves), that procedural knowledge is really, really important. It's just too easy to fall into the trap of "Oh, I'm a smart person who reads books and Wikipedia; I'm fine just the way I am." Maybe you can do better than most college grads, simply by virtue of being smart and continuing to read things, but life (unlike many schools) is not graded on a curve. There are so many levels above you, that you're in mortal danger of missing out on entirely if you think you can get it all from Wikipedia, if you ever let yourself believe that you're safe at your current level. If you think school isn't worth your time, that's great, quit. But know that you don't have to be just another dropout who likes to read; you can quit and hold yourself to a higher standard.

You want to learn math? Here's what I do. Get textbooks. Get out a piece of paper, and divide it into two columns. Read or skim the textbooks. Take notes; feel free to copy down large passages verbatim (I have a special form of quotation marks for verbatim quotes). If a statement seems confusing, maybe try to work it out yourself. Work exercises. If you get curious about something, make up your own problem and try to work it out yourself. Four-hundred ninety-three pieces of paper later, I can say with confidence that my past self knew nothing about math. I didn't know what I was missing, could not have known in advance what it would feel like, to not just accept as a brute fact a linear transformation is invertible iff its determinant is nonzero, but to start to see these as manifestations of the same thing. (Because---obviously---since the determinant is the product of the eigenvalues, it serves as a measure of how the transformation distorts area; if the determinant is zero, it means you've lost a dimension in the mapping, so you can't reverse it. But it wouldn't have been "obvious" if I had only read the Wikipedia article.)

forces conspired to make me not succeed.

Forces don't conspire; they're not that smart.