I guess the only type of sex that anyone can claim to "understand" is procreational sex, performed only when the woman is ovulating... in that sense, I can understand how sex was once necessary for the survival of our species, but thanks to medical technology, that's no longer the case. Beyond procreation, sex is purely an expression of desire, with the single goal of giving or receive pleasure, and it's completely, 100% subjective.
Nobody else's pleasure is dependent on my understanding, and we all like what we like. It took me a long time to figure it out, but I've finally realized that you don't have to understand it to enjoy it. :tongue: