Sir Michael Caine "laughed for five hours" after smoking marijuana for the first time.

Sir Michael Caine

Sir Michael Caine

The 85-year-old actor drank alcohol "quite heavily" during his younger years, but he was completely overwhelmed when he tried drugs for the first time.

He shared: "I knew all the Beatles, all the Rolling Stones. I knew everybody in the music business and we spent our lives in discotheques. I drank alcohol quite heavily for some time. But I never did any drugs.

"I was at a party with [actor] Richard Harris and I said, 'I've never smoked marijuana,' and he said, 'Well, smoke one.' I smoked the marijuana and I must have been terribly tense, because I laughed for five hours."

In fact, Michael couldn't even convince any taxi drivers to take him home after the disco.

And the Oscar-winning star's doctor later warned him about the potentially damaging impact of drugs.

He told Rolling Stone magazine: "I couldn't get a taxi home because I was standing at one o'clock in the morning on the pavement trying to wave a taxi: 'I'm not picking him up, he's nuts or drunk.'

"Also, I was told by my doctor not to do it. He said, 'You're an actor, you've got to remember lines, and marijuana is murder for the memory.'"

The 'Kingsman' star was also a heavy smoker earlier in his life but the death of a friend convinced him to abruptly kick the habit.

Asked whether it's true that he used to smoke 80 cigarettes a day, Michael replied: "Oh yeah, and they were French cigarettes, Gauloises, one of the most extremely powerful brands you could think of. They weren't even cork-tipped to filter them a little bit.

"But I was watching television in England, and there was a snooker player I knew who had lung cancer and had lost his voice and had the thing in his throat to speak. I've never smoked again."