All the time, believe it or not. For example, in one class, I learned about garbage collection algorithms, which I used to explain to a coworker why he was seei

All the time, believe it or not. For example, in one class, I learned about garbage collection algorithms, which I used to explain to a coworker why he was seeing a certain memory usage pattern in the JVM. I'm also glad I learned about DFAs and NFAs in my theory of computation class, because they come in pretty handy for figuring out some problems. My favorite incident was when the same coworker was suggesting project ideas, I used Turing's halting theorem to show him that his idea was impossible. Granted, that doesn't happen every day.