Mainly, I just grew older, I think. I realized that it's very easy to be dismissive, and not actually clever. Also, thinking positively makes me feel better, and it's a more useful mode of thinking. I remember vividly the first time I did mushrooms, I felt like I was way too much of a negative person, and I strongly felt that it was wrong. I don't know how much of an effect that ended up having on my personality, but I think it did make me more aware of it.
Altered states of consciousness can lead to new ways of thinking. I was on some mushroom extract -- who knows what we were taking back then -- on Salt Spring Island (B.C), on the beach looking at intertidal lifeforms, seeing into the life of things. I decided then and there to take a biology course. Brings to mind Wordsworth's line from Tintern Abbey While with an eye made quiet by the power
Of harmony, and the deep power of joy,
We see into the life of things.