Can college students get grounded?

Growing up is so confusing. I graduate high school get told to pay for college on my own, that if I don't get over my mother issues that I'll get kicked out. But I find a big flaw in that because if I get kicked out who will watch my brother? My mom? hahaha that would be a sight...her actually watching her own son. Now I am 18 and a college student but I live at my parents home, so do I have to ask permission to do things and go places? I have a curfew of 2am which I really think is pointless because if I'm out at 2am then why even have a curfew, if I'm out that late normally it would be safer if I just stayed put. These questions have come into my head when my best friend Tierney invited me out on her boat for the night. My mom has just got back from a month long "vacation" which she left and came back with out telling me anything, and I have been gone for a majority of the week so I have this feeling if I ask that my parents will say no because I have to spend time with my mother. BUT I really don't want to be home, my dad is working nights so it would just be my mom and brother and myself. I will go crazy. I think I'll ask and if they say no then I'll still go because I am a damn adult and there is no reason why I should be stuck at home. I have asked my dad if I could do something and he said I couldn't because I had to babysit my brother and that my baby sitting is like my rent.This happened when my mom was still in Arizona. So maybe it was a one time thing or maybe not.But the question that I still haven't answered for myself is do I have to ask permission to do things? Or do I just inform my parents of where I am going to be? All of this would go away if I just had a job and moved out.