In the US, it very much depends on the circumstances. In the Black community most of the time you're allowed to come back home especially if you intend to contribute in some manner to the household, whether physical or financial. When I left college about 24 I came back home to live with my mother. I was jobless but started working a year later and began contributing to the household of me, my mom, and two little sisters. I got a car and started taking everyone in the house to their various appointments and became my mom's primary caregiver when she got sick.

So sometimes (at least in communities of color) we come back home, or sometimes never leave home, or invite parents to come live with us as they grow older and we become their caregivers. Leaving one's family isn't a hard and fast rule in the US, and most of the people I've met who were disenfranchised from their families were white, (although that sometimes does happen with black families too.)