At what age does it become unacceptable to live with your parents?

Personally, I haven’t lived with my parents since age 18. I went off to college and lived in apartments with friends during the summers my first two years (when we were required to live in student housing). Having my own apartment was always a priority for me, as my parents and I have an excellent relationship, but only when we’re not living together.

However, I know this isn’t the case for everyone. I understand living with parents for a year after college (if you’re not going to grad school) in order to get your bearings while starting your first job and save up money for your own home. In most circumstances, however, I think that it’s not really appropriate to live with your parents beyond age 23.

There’s always the stereotype of the “guy who still lives in his parents’ basement.” At what age do you think this stereotype becomes relevant—that it is no longer acceptable to live with your parents?