Same here. I was at least intellectually honest enough with myself to admit I didn't know what either party stood for as a teenager, so I'd registered as an Independent. After Carter I was so disgusted with all politics I don't think I voted again until Bush #1. When Slick Willie was elected that turned the tide for me and I registered as a Republican.
Before I made it official I suppose I was well on my way after I read ANTHEM by Ayn Rand in 1977.