John Cleese, the now-85-year-old comedy legend, was “surprisingly ignorant” and was never “interested” in drugs as a younger man. But in 2005, he decided to try the potent hallucinogen LSD (lysergic acid diethylamide), which “can alter a person’s perception of reality and vividly distort the senses”. He took the drug under supervision, and was left in amazement at the effects.
He told the Times’ Weekend magazine: “I just wanted to know what it was all about“. “The man was one of the world experts on it, so I felt perfectly safe..
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John Cleese took LSD at 65 to see ‘what it was all about’

He tried the hallucinogen in 2005 and said he was amazed by the mind's 'fertility'.