No beer for you, Sir

How stupid are US rules?

Tried to buy a beer in a bar the first time we went to Beale Street two days ago. The bartender looks at me and asks me for an ID. I am flattered, I look like 21?

I frantically check my wallet. Forgot the Philippine driving license in the Philippines. No other ID. Nope. I won’t get a beer in this place. I am definitely one of these ultra fast aging teenagers. Strange country, this one