I'm 67 and am told I look younger. However, young people know I am old. Even though I'm the size of a 12 year old, I have gray hair and lots of people open the door for me. Children were sometimes puzzled by me when I was younger, but well into adulthood.
I never had to show my license to get liquor because I don't drink, but I'm sure it would be frustrating for people not to believe you're old enough to get it. But you're likely to appreciate looking older when you get into middle age, LL!

Maybe you can try a gray-haired wig!