I'm 33, single and still live at home. Would do anything to still be in my 20s as the stigma of living at home isn't anywhere near as bad as being in your 30s.
6-7 years ago it was relatively all ok as most of my friends were in the same boat but that time just seems to have passed by and now all of those friends have managed to get girlfriends which in turn makes it easier to move out through sharing of rent, bills or putting together a deposit to buy.
Now my SAD is even worse than back then because I am in that catch-22 situation where it is even harder to try and find someone of the opposite sex to even go on a date with you (try mentioning to a girl you are 33 and still living at home with parents) and because I am single I cannot afford to buy or rent... I live in London where it is nigh on impossible to move out as a singleton with the high property prices.