No matter whether you're 21 or 35, your parents will expect you home at a reasonable hour on a school night and you coming home at 6am on a Saturday morning will not be acceptable to them. You can't be a student forever and although you still have a full time job, you're only supposed to be having part time fun. Most of your arguments will be about the time that you come home and if you say you'll be back for 9pm you better make sure that you are. You may be on the rise to being a manager at work, but your dad will still totally ground you.
