Yes - the THREE theory!! I grew up with that one too. People would die in threes, celebrities and locals alike. I believe people are hardwired to seek patterns. I'm sure the could find two or twenty bad things in a week, or GOOD things happening in threes, but we are also wired for remembering negative vs positive events, as a survival mechanism. I'm also not superstitious, but it's fun to look for connections, synchronicity, patterns, and meaning in a world filled with seemingly random events and inexplicable chaos.