How old is too old to live with yoru parents?

At 18 or 19 a "kid" should be able to help financially if they decide to live with their parents. However, different cultures have several generations living in the same house. It also depends on the kid, what the career path involves, disabilities.... etc... However, I lived at home until I was 25 working my way through college and a masters program with a child. I helped financially and with the household duties. You don't want to enable your children by being dependent on the parents, they need to learn about responsibility to one day survive on their own in the adult world. I worked my stay and now I am a Licensed Counselor.