I do have a friend who is older than I. He's 34 and still lives with his parents. I also know others that are 30 and older and still live with their parents as well. It must be a midwestern thing because I did not see that out west or when I lived in the south either.
Indeed, sometimes stuff happens that doesn't really allow for ideal situations. I was lucky in that I was never needed to pull money into the house. Anything I earned went towards my own stuff, which typically meant gas, food, and other necessities (and of course my own entertainment). So if nothing else I was taking a little burden off of my mom even if it wasn't totally necessary. The last time I asked anyone in my family for money was when my last car broke down, which an $800 auto bill is not an insignificant expense. However, I paid my mom back as soon as I could too. Otherwise I've been fairly self-reliant since I started college.
I stayed at home until I finished college in December 08. Right out of college, I was making more money than my dad ever did (my mom still has me beat though, but she's got her masters and is in a supervisory position). By the end of July last year I had moved out into my own home. Oddly enough, my dad is currently is back living with his mom at the moment. XD He's got his reasons, to keep her company, to save money (retired military), and so forth, but it's still pretty odd for a guy in his mid-40s to still be living at home. He'll be moving out when he gets remarried soon though.