Los Angeles is certainly known for having more than its share of massive egos, and often those egos are kind enough to announce their presence via sickeningly overconfident vanity licence plates. I'm sure we've all seen vanity plates crowing about how hot or rich or awesome the driver allegedly is.
Luckily, some people, like Conan O'Brien, understand that genuine humility is worthy of immortalizing on aluminum via prison labor, and showed some great examples of that on the show. Enjoy the humble.