Is it possible to change your date of birth on your birth certificate?

I know a bloke who is 42 years of age and he wants to change his date of birth on his birth certificate from being 42 years old to 20 years old because he does not want people to think that he is 42.He is afraid of getting old and he is pretty good at holding back his age.He thinks that all of us should change your age.Do you think that he can avoid getting old?Is it possible to change your date of birth on your birth certificate?
no, changing a birth certificate--which is a legal document--is illegal.
No, i don't think you can do that. Besides, people are going to know he isn't 20 years old, if he's really 42.Is it possible to change your date of birth on your birth certificate?
of course you can do thatIs it possible to change your date of birth on your birth certificate?
?.....
ahh no.