Well, from the other side of the pool ... I look my age, more than any woman I know (so I guess I look older than my age, then?). When with friends, I'm always the only one that get "ma'am-ed" (early 30).
So I may be the only one to say : yes, guessing my age right hurts (and know what hurts more ? "Guessing" I'm older than I really am. Been there ...).
Especially since it seems so unfair : I wear sunscreen, moisturize, eat my greens, exercise dutifully and dress (I hope) stylishly. I could blame it on genes, except my mother and grand-mother have aged very well
Enjoy your good looks, everyone !