Interesting thread. I wouldn't have posted on it in 2002 because I was still in my "I can't be bothered with makeup" phase...
When I was in middle school, I noticed some of my classmates wearing makeup. (We're talking 11yos here. A lot of them didn't know what they were doing, and wound up looking like they should be working a street corner.

) So naturally, I started bugging my parents about wearing makeup. I never knew there were so many variations on the word "no".

I was allowed very pale lip gloss and that was *it*.
When I turned 13, my mother took me to the Clinique counter at the local Macy's for a makeover. I was restricted to light colors, but got foundation, powder, blush, eyeshadow, eyeliner, and lipstick (as well as some things from the skin care line). I was shown how to apply it, and my mother said I could wear it as long as I wore it correctly - if she saw me looking like a hooker, no more makeup.
I stuck to Clinique through high school. When I got to college, I found I didn't have the time to "put on my face" every morning, and gradually stopped wearing makeup at all. Only within the past year or so have I gotten back into it. I save the full eyeshadow/lipstick/blush thing for special occasions, and just throw on some lip gloss most days. (I wonder what my 11yo self would have thought of
that ... lol)
I have no brand loyalty, though. I have a mixed bag of Clinique, MAC, Prescriptives, Estee Lauder, a couple of no-name items, and even a tube or two of the dreaded mood lipstick (I love it, it's very long lasting!).