I think men are different one from another too but generally faster? I think since sex is on their minds more and their "spot" is obvious there, outside themselves and doesn't have to be "hunted" for sometimes :-) they'd naturally be quicker. And they have wet dreams and other experiences as boys (going over hills) that feel good so they get the message, kind of like with toilet training and boys tending to get it faster because it's more obvious.