In any case, my point isn't that people should receive some benefit based on maturity. It's just the opposite. We live in a society where kids at 12 can have credit cards, at 16 can drive, etc. It's perfectly fine, imo, to allow people to do things while they are still immature to some degree.
The "guy who makes the rules" is the guy who votes. That's people 18 years and older.
Har. Lemme guess...you're 36?
The problem with age as a metric of "growing up", is that the cutoff is always older than you are, but younger than the guy who makes the rules.