Sabine Baring-Gould

Incontestably, the great centres of population in the primeval ages were the chalklands, and next to them those of limestone. The chalk first, for it furnished man with flints, and the limestone next when he had learned to barter.

We exist in this weirdly schizo culture, where sex is everywhere in the media, and yet, at the same time, you don't sit down and have a conversation about what you did in bed last night with your friends. Despite the ubiquity of sex, it's still a taboo when it comes to day-to-day conversation.