Hair Color Makes the World Go Round

I remember when I was little and watching my Mom color her hair (or frost, as she would say). I thought it was the coolest thing and started to frost my baby dolls hair by using baby powder (that's the same thing, right?). So, it's no wonder that I grew up and started dyeing my hair whenever I could. By now I've had almost every color hair imaginable. But why is it that when my Mom told me she dislikes my new hair color, I derived a certain pleasure from that? Does that teenage rebel live on deep inside? I'm 35-years-old, for goodness sakes. Should it really matter when my parents disapprove of something I do?