The Big Chill

I am getting the cold shoulder from my mother. I suppose I should enjoy it, but it is, to say the least, unnerving. I didn't want to go home after work, so I came to my friend's house, where I was plied with dinner, cheap wine, and promises of a catnap. Yet it has been four hours since I left the office, and not a single call from my mother OR my father trying to findout where I am. I guess since I am 25 years old it shouldn't matter, but I generally let them know where I am. Ever since last night's events, which only got worse after my previous post, I haven't been scrambling for the phone with any eagerness to speak to my mother. Does me not calling her to tell her where I am make me equally guilty?
I guess my reasoning behind this is to show my mom that I'm not the "spoiled, ungrateful little bitch" she seems to think I am. I don't know if she even gets that what she said really hurts. I'm not "given" everything like she says I am. I pay for everything on my own except rent. I buy my own food, pay for my own medical and insurance expenses, and don't cause any trouble. My room may be messy, but I don't bother anyone, and I'm not out getting drunk every night. I have good friends and a halfway decent job that I show up to every day. I generally let both of my parents know where I am and what I'm doing (within reason) each day. I really don't understand why she acts like this toward me. Menopause, perhaps?
Maybe we'll be over it in a few weeks or days, but for right now, I don't really want anything to do with her.