Jack Nicholson describes his first acid trip in a 1972 Playboy Interview:

Jack Nicholson:

I was one of the first people in the country to take acid; it was in laboratory experiments on the West Coast about nine or 10 years ago. At that time, I was a totally adventurous actor looking for experience to put in his mental filing cabinet for later contributions to art. I was very curious about LSD. Some of the people I knew were in therapy with it. I went to downtown LA and took it one afternoon. I spent five hours with a therapist and about five more at home in the later stages of it. I hallucinated a lot, primarily because of the way the therapist structured it. He put a blindfold on me, which makes you much more introspective, gives you more dreamlike imagery. Imagine what acid is like when you know nothing about it. You think it’s going to be like getting stoned on grass, which I had done. But all of your conceptual reality gets jerked away and there are things in your mind that have in no way been suggested to you: such as you’re going to see God; or watch sap streaming through the leaves of trees; or you’re going to feel the dissolving of certain bodily parts; you’re going to re-experience your own birth, which I did on my first acid trip; you’re going to be frightened that your prick might be cut off, because you have castration fears; you’re going to come mush-ass to face with your own homosexual fears. I just wasn’t ready for half this stuff.•

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Nicholson invests in hydrogen cars, 1978: