i'm curious about the evolutionary benefit of crushes; short(er) duration intense feelings for someone. they probably are not directly about sex, per se, as they are generally unidirectional. not that sex cannot be unilateral (i.e. coerced) but both sexes have crushes and that does not line up with size differences between them.
maybe they are ways of training your brain what to look for. if particular paths are reinforced often enough they stick around and have a strong pull. but that assumes crushes form around the sorts of individuals you should pair off with and that's at least as often not the case as it is.
which is to say, i wonder why i am drawn to the people i am drawn to.