We've decided it might become a trend. You know start one now rather than jump on the bandwagon in a few years when it's so popular.
My original post was going to be on some historical thing, but now it's on character quirks. I once read a book (I'm terrible at titles and this was so long ago I couldn't tell you an author if you wrote it out for me) where the heroine never cursed. She had a potty mouth and bet someone that she could stop cursing anytime she wanted. Instead of even a simple 'damn,' she used wild terms to express her curses. It was a small point story-wise, but it obviously stuck out in a story that I otherwise couldn't tell you a word of.
Quirks go to characterization, to rounding out your plot. What are your favorites? What are so annoying that you couldn't even finish the story because of a trait? What are your character's idiosyncrasies?