I studied computer science at a university, not just a college, and coroutines weren't covered during the course. So even if you've got a degree, there's no guarantee you'll have met a coroutine!

(I do agree that a formal education is valuable, even if you already think (or know) you're good at programming. I learned a lot from my course. There's a lot to be said for being forced to learn a bunch of stuff, and when you're under 25 it's not like it's going to hurt.)