I once heard Terry Pratchett (at Hay, I think) muse on how odd it was that shops purporting to sell "adult books" invariably sold what could only be read with pleasure by a backward 14-year-old...

Whenever I go to Newcastle I keep meaning to visit the Adelaide pub and never get around to it; it was owned by the music-hall singer-songwriter Joe Wilson, whose work I like very much. He was teetotal himself but used the profits of the demon drink to finance his writing...