When I was 19, I read Alan Watts' The Book: On the Taboo Against Knowing Who You Are. After that, I was sure there was nothing else I needed to know in order to live intelligently. It was, I thought, a compendium of the best insights worth knowing. My certainty eventually faded, thank Goddess.
In its place came the understanding that life's mystery just keeps getting deeper and vaster as one grows older -- that it's idiotically arrogant to ever think you've got it all figured out. A healthier approach is to cultivate a capacity to be endlessly surprised. I hope you'll do that in 2009, Gemini. The flood of novel ideas and fresh perspectives surging your way will warrant it.