Indie Gaming slant on these following examples, and I suspect that this sector is above average for this type of thing, but I suspect if I looked I could find many dropouts in other fields. On the other hand, Carmack dropped out of college, Jonathan Blow dropped out of college. Markus Persson dropped out of high school. Eric Barone never found a job despite graduating from college. All of these people are out-of-this-world fucking good, but were not at the time that they dropped out, which means according to your guide should not have gone on to create what they did.