Some people think it's psuedo-science, but it's called morphic resonance. It's when someone thinks of an idea, it makes it easier for someone else to think of the idea. That's why you should do crossword puzzles later in the day, because other people have thought about the answers. That's why you hear about people coming up with inventions almost at the same time, because someone else is thinking about it. That's why whenever I have a really good idea, I'm always worried about theft.