Just to entertain the idea. Let's say that if you want to go to college you get the money at 18. If you want to buy a house you get the money at 20. If you want to start a business; you get 100k at 22, and 150k at 26. To ensure that you are mature enough, and have a chance to fail(and learn) once.

I know that adding rules makes things more complicated and can have unintended consequences.