As kids and teens, most of us take for granted everything our parents do for us. Then one day we move out on our own (hopefully), and suddenly we realize, damn, things like paying bills, doing laundry, buying groceries, and cleaning the gook out of the sink are no joke. No wonder mom and dad were so pissy all the time.
When I first moved out at age 18, there were many aspects of independent living that I was in no way prepared for. Sure, I could stay up as late as I wanted watching TV every night, but I also had to step up and take on a bunch of responsibilities I never expected to be quite so hard. Some of them I'm still getting used to.
It's almost enough to make you want to give up your independence and move back in with your 'rents. JK JK JK JK JK.