Comment by johongo

It was a typical attitude among my physicist and mathematician friends that memorizing was for suckers, even though it was often required to reproduce long proofs or derivations. These were people to whom mathematics came naturally; their understanding, memory, curiosity, and experience just compressed that knowledge until it was trivial to memorize. Unfortunately, many walked away with a sense of not needing to know things until they need them, but good luck with that in a systems design interview.