I'm 34 but everyone assumes I'm about 23-26, including a bunch of co-workers aged from 18 to 60 odds. I guess it's quite handy because I still like going to clubs and having a wee dance, so not looking as out of place as I probably am helps I guess.
It's funny how some fairly young people can have the reverse and can look more like 40, a hard paper round as we say here. Would much rather be babyfaced and age semi gracefully than look like I should be dead when I hit 50.