I sure wish someone would explain this to me!

I don't get it!? When I take one of my daughters anywhere.... people comment on what a wonderful person she is. Really she is, but what I don't get, is how totally disrespectful she is to me. Is the age 14 1/2 really suppose to be this awful, for me??? Yeah, I know I signed up for this motherhood thing...but I didn't , or don't remember, signing up for this shit! I cannot believe how hateful she can be to me. I would really hate if something were to happen to me, and her last words to me were , Whatever, or, just get out of here! She would feel awful, and she would have to live with that for the rest of her life.... I think. I share this info with my mom, and she says to me, really, this is funny....I beg to differ with her. I suppose since she has already raised 5 kids, she can afford to laugh at all of this. She does tell me though, she would have never thought of being disrespectful to her parents, and I would have never thought of saying those things to my parents, either. So, is it a generational thing, have I become too loose as a parent? I don't even know where to begin with punishing my daughter for her behavior...or even if I should. Damn all of these so-called-parenting-books, all of the Dr. Phils, all of these people that say my generation are raising kids wrong. My parents, and their parents, just shot-from-the-hip, and did what they felt was right, at the moment, and I turned out o.k. A friend, not to long ago said to me, "teenagers are the way they are, so it won't be so hard to let them go one day".....I'm thinking she is so right. The little voice in my head says to me, "this too shall pass"...God, I hope I'm right.