For me it had to have been that women will never love you, and that even if you think you've built a "connection" with her, it will always fizzle out. So there is just no point. Women will never love you how you expect to be loved. The hard part is thinking that you will never have a family and settle down with "the perfect women for you" and will not be loved. Its only for a month, year, two years, etc.

So now I accept if I begin to like a woman, and get feeling for her after a short while, I'm gonna be kicked in the nutsack later on.

Theres where the term is "She's not yours, its just your turn."