In our youth, desire can be indiscriminate. A young man's relationship with his sex drive is like a dog-walker's with an ill-disciplined dog: he is led from pillar to post without hope of discipline or control. Some men, no matter how old they are, will never stop chasing women for sex.
But for most of us it's different. We've realised that girls, instead of being the pointless, silly creatures we took them for, are the most amazing, fascinating, desirable creatures on the planet.
They can make your heart soar with a glance, and crush your spirit with a sneer.
Women don't have to do anything to hold men in their power. Just existing is enough.
Why else would men have written countless poems and love songs? Why else would they have painted them, sculpted them, gone to war for them?
It's men, not women, who are the true romantics. We want sex because it feels great, reinforces our self-worth and, for us, physical intimacy is the proof and expression of emotional intimacy: to be denied sex is to be cast out.
This makes sex as frightening as it is intoxicating.
We hate to admit it, but we are dependent on women and worry about our ability to satisfy them.
In this Sex And The City age, we fear that every act of love will be analysed over cocktails like a premiership game on Match Of The Day.