Sex, whatever else it is, is an athletic skill. The more you practice, the more you can, the more you want to, the more you enjoy it, the less it tires you.
Robert A. HeinleinConsider the black widow spider. It's a timid little beastie, useful and, for my taste, the prettiest of the arachnids, with its shiny, patent-leather finish and its red hourglass trademark. But the poor thing has the fatal misfortune of possessing enormously too much power for its size. So everybody kills it on sight.
Robert A. HeinleinLuck is a tag given by the mediocre to account for the accomplishments of genius.
Robert A. Heinlein