"Coming of Age" is a somewhat amorphous proposition for males in modern Western societies. It has something to do with recreational activities conducted with females in the back seats of cars and perhaps buying a flat-screen television. But there are no clear moments when the world turns to you and says, "today, you are a man." And this is not necessarily a bad thing.
You could, for example, be a member of the Brazilian Satere-Mawe tribe. They have a very clear way of indicating the arrival of manhood. You need to wear a pair of gloves -for at least ten minutes, 20 times over - filled with Bullet Ants. These inch-long insects have the most painful sting in the world, described as "waves of burning, throbbing, all-consuming pain that continues unabated for up to 24 hours". One sting is 30 times worse that getting stung by a bee. In short, Bullet Ant gloves are really, really uncomfortable. Here's a video of this insanity (not for the faint-of-heart):
Ow. I'll keep my ambiguous passage into adulthood, than you very much.