anecdata here: I once was asked to explain the difference between 2 functions in a standard library that I don't think I had ever used. That was the only ques

anecdata here: I once was asked to explain the difference between 2 functions in a standard library that I don't think I had ever used. That was the only question I was asked. They completely wrote me off as soon as I couldn't answer the question. If they had just asked me to write an entire app from scratch (not counting frameworks) I could've done that for them no problem :)