1. A parent wakes you up at 9:30 am on a Saturday because "it's getting really late."
2. The appliances are in completely different places than in your kitchen.
3. The tap water tastes gross now, and there's no Brita filter in sight.
4. You're third in line for a shower.
5. Your bedroom walls are bare, save for the cheesy kid art you chose not to take with you in the move. (And god, that wall color ... what were you thinking ...)
6. You are dependent on the kindness of car loans to get anywhere of note.
7. All the friends you want to visit who live here have regular, ongoing lives of their own ... and you're not a part of that anymore.
8. No roommates.
9. You spend every minute visiting, whereas once you simply lived there.
10. TV channels have the gall to be numbered differently. Worse, there's no DVR.
11. You feel like you're interrupting someone's comfortable routine.
12. Your mother will never admit this, but she's moved on since you moved out. So now, you have to carve out a space for yourself, instead of occupying the one you thought you'd always have.
13. It forces you to admit you're a grown-up.