About being a man: the thrill of discovery fades a little over time, but not much.
When you’re a teenager and first slipping your hands under blouses, everything is unfamiliar.
Now, the expectancy is tempered by experience; you know what you’re about to get.
However, a new woman rejuvenates the explorer’s wanderlust, adding to the thrill and thereby amping up the experience to near-teenage levels. Role-play can have the same effect.