I've been told...
On more than one occasion, and by more than one person that I look no older than 27 :)

I'm 40.

Mind you, with the beard, I look older (probably 50 or so)
( snee held his breath since, Tue 9 Dec 2008, 16:23, 1 reply)

Conversely, a friend of mine
Who has had the mixed blessing of excessive testosterone, and hence has been going bald since the age of about 17, was accosted whilst walking past something like the East India Club near Marylebone. This old gent came out and started talking to him as if he knew him.

"I'm sorry, I think you've mistaken me for someone else." He politely proferred.
"Oh, I'm sorry, I thought you were [name]...he comes in here quite regularly."
"...so you think I'm a man of approximately what age?"
"Oh, about 40."
(LongJohnBaldry, Tue 9 Dec 2008, 16:27, closed)