Whilst I agree with you on being self-taught and knowing those answers I will say that I finally went and got an MSc in Computer Science after 12 years working professionally as a developer and being self-taught.

Part of the reason was to find out what I didn't know.

What I didn't know was basically some parts of set theory and quite a chunk of automata theory.

I did find cperciva's questions to be trivial, but I wouldn't say that makes them trivial. A TV quiz once said, "It's easy when you know the answer.".

Algorithms for someone else might be what automata theory was to me.