These days they'll live w/ mom & dad into their 30's.
I was 19 when I got home Sunday morning (hung over), just when Mom & Dad were leaving for church. Dad said, "are you coming or going?" "Coming" I said. Dad said, "Pack your stuff, you're leaving!"...… I was gone when they got back from church. Moved back in a few years later, for 3-4 months after my hitch in the Army. Been on my own since. That was a long, long time ago.