Why?

Why were the Ninja turtles names after artists? Why do people always cite the same novels when asked for the best opening line - 1984, Pride and Prejudice, a Tale of Two Cities and the one about bloody Manderley? Why don't people use their indicators to indicate where they're going? Why does the post person come half way through the afternoon during the week, but never fails to wake us up at 8am at the weekends? Why can I never remember the name of a single song I want to add to my playlists when I get to Finetune? Why do people say 'getting along like a house on fire'?