Lol Sam that would not happen in the US, I know the rest of the world is so relaxed about drinking age standards. When I was in Germany in May I never got asked for ID and I am 20. Here in the US my mom gets asked for ID at grocery stores and she's 47- the cash register machines will not let the cashier close the bill unless they manually enter the customer's date of birth.
At a bar it's different though and they won't ask unless you look young. But I've been a waitress and they said anyone who looks under 40 you should ask for ID because if the cops come the waiter gets arrested and restaurant gets their license taken away!
I attribute this strictness in the US to the bad parenting
If parents were careful enough, even if there was no drinking age, there still wouldn't be drunk kids and teenagers, and that's a proven fact in many European countries where it's even less common to see teenagers drinking irresponsibly than in the US/
Thats not to say that parents in the US are bad- just that there are more bad parents than there should be