The teachings of Don Juan: A Yaqui Way of Knowledge. Far from the first time I've read this or the other 8 main books by Carlos Castaneda but with my user name what do you expect?
That is one tripped out book. I read that, and one or two if his other books many years ago. A very good way for me to challenge my way of thinking, get totally different perspectives. Thanks for reminding me that now is a good time to re-read them.