I can relate to the whole "mom's don't listen" thing. MIne has yet to accept that I've been out of the nest for 14 years. As someone I know once said, I may not be a momma's boy but that woman is a boy's momma. I think it's some sort of genetic reflex triggered by expelling a child from the womb.
Its a shame that your mother doesn't really hear what you are saying. I've had less of a problem with this with my parents in recent years, but it still does pop up from time to time (for instance, I don't often tell them when I'm feeling miserable because I'm afraid they'll think I'm whining). Just keep in there with her, eventually she'll come around; sometimes its really hard for parents to see you as an adult who can make thier own decisions rather than as a 12 year old kid.