Indeed something rare
"The truly lucky people are the ones who manage to become long-time friends before they realize they are attracted to each other. They get to know each other’s laughs, passions, sadness, and fears. They see each other at their worst and at their best. They share time together before they get swept up into the entangling intimacy of their sexuality. This is the ideal, but not often possible. If you fall under the spell of your sexual attraction immediately, you need to look beyond it for other keys to compatibility." An interesting blog post from my friend =)