In college an old physics professor of mine once told me that you don't really know something until you can clearly explain it to other people. And you can't ex

In college an old physics professor of mine once told me that you don't really know something until you can clearly explain it to other people. And you can't explain things to other people unless you have the basic concepts memorized. I think about that every time people complain that it's not fair for interviewers to ask them to explain basic programming concepts.