The B'nai Mitzvah, Confirmation and Sünnet:
Putting aside the religious justifications, each of these have traditionally been performed as the young child is about to enter adulthood. Maybe in the ancient past, but do we really consider the entering of puberty to be the onset of adulthood? It may be argued that adulthood is increasingly delayed until reaching well into the 20's or 30's if it is ever reached at all.
Teachers that I know tell me that girls are almost always the brightest students in their classrooms, even excelling in the traditionally male domain of mathematics. While the boys have been spending their days playing video games and raving about Jackass The Movie, the girls have left them behind and are beginning to realize that they don't need men to complete them. This spells trouble for us guys. If we're not careful, these developments along with the current advancements in reproductive technologies may eventually make us obsolete.
I am more likely to dance in front of complete strangers than friends or family. I don't know exactly why.
Twins within the womb compete for resources. What determines success? Location, Location, Location.
Fibonacci Numbers are still amazing.