Too old to be living at home?

I have a friend who is 29 or 30 years old and who is still living at home, with no real anticipation to move out. He is an only child. Before we were friends I think he thought we might have the possibility of dating, but that has always been a turn off for me. Do you think this is normal? I know differnet cultures have different standards. I just always felt like it was important for a man to grow up and be a man. What do you say?