If you haven't learned to autodidact by the time you get a "real" job, you're at the mercy of whoever signs the check to send you to workshops or courses. That's not a good position to be in.

Another reason to autodidact is to increase your opportunities. If you wait until someone pays you to learn something, you miss out on having the skills when the hiring/team assignments happen.

My current autodidact list includes using a particle simulation system with dampened springs to draw social network diagrams. Aside from learning something about social network analysis, it's an excuse to refresh on vectors and (simple) differential equations, and I hope it'll make for a snazzy demo for my next round of interviews.