You get ideas from daydreaming. You get ideas from being bored. You get ideas all the time. The only difference between writers and other people is we notice when we're doing it.
“While all the other kids were out playing ball and stuff, I used to stay in my room and imagine that there was a camera in the wall. And I used to really believe that I was putting on a television show and that it was going out to somewhere in the world.”