I had a buddy in the Navy that was doing a good Cpt Picard impersonation at 25, AND was missing all his teeth from some weird gum disease.
I also knew a kid in high school that was able to grow a decent goatee at 13, and a full beard at 15. He bought the beer.
My best friend in high school had a hairy chest and beard by the time we became friends around 16. Who knows when he sprouted though, probably at least a couple years earlier.
I always felt bad for my guy friends who started losing their hair in their early twenties. I always thought it made them look more masculine, and in general, they looked just fine. But you can’t tell a guy in his twenties he looks good with less hair. They never believe you, even if it’s true. I myself, was hyper paranoid I’d lose my hair so I know how they felt. I wish I owned stock in Rogaine; young guys who even suspect their hair is thinning gobble that stuff up.
Luckily, I never did lose my hair. At least not yet. Everyone in my family has a slightly high, receded hairline though. Guys and girls. Not enough to look like it’s receding, just sort of high, if that makes sense. The middle foerhead has hair, but the - I dunno - temples I guess, recede.