Which is reasonable, since it's your time. But consider that I have three degrees in CS (BS, MS and PhD). I am employed doing CS research, primarily in systems

Which is reasonable, since it's your time. But consider that I have three degrees in CS (BS, MS and PhD). I am employed doing CS research, primarily in systems and high performance computing. And for at least one question on each subject, I would not feel comfortable answering unless I referred to some reference. (Yes, even the architecture and systems questions, despite that being my "expertise": I can recall very little about coherence algorithms.) The primary value of a formal education is, I think, not that you know a lot of stuff. Rather, it's knowing what you don't know. Knowing just enough to recognize "Oh, this is related to that other thing, I should go and read about that." I'm constantly doing that, as are the people I work with.