I have to think Ayn Rand must never have had any truly satisfying sex in her life, because, as anyone who's ever had an orgasm can tell you, you're not really thinking 
about yourself, and certainly not the glory of yourself, at that point. (Maybe later.) You're not really thinking about the other person, either, except for maybe with some vague gratitude. The point is that you're not thinking. Sex, and its occasional bedfellow, love, remains the great equalizer: everybody loses a little bit of themselves to their partner, and they get something back in return. The more you give, the more you get. Love is the same way — when you've found someone you can't help but put above yourself, someone whose needs and wants and weird little foibles you would die to fulfill and preserve, you lose yourself as an individual. In this instance, Rand's "I" is the ugly word, the monster. People tend to give couples shit when they shift, all giggly and happy, into "we," but that's an important moment — it's a mindset shift as much as a romantic one.