Syag – great reply, and totally along the lines of my own thinking. Sometimes, in our zeal to BE ourselves, we forget that maybe, just maybe, mom or dad happens to be correct. Being stubborn for its own sake, is not a sign of maturity (not accusing you of that, just making a comment), and sometimes teenagers (even at 19) dig in their heels just so they can say they did it THEIR way. Try seeing things from your mom’s perspective. ALWAYS be respectful, even when you don’t agree.
I promise you, and I know this from personal experience unfortunately, when the time comes after 120 years and your mom is no longer around to give many “helpful suggestions” to you, you would give anything for her to be there, so you could continue to be mechabeid her.