Speaking in a new BBC Scotland documentary series, which recalls how Connolly revolutionised stand-up comedy with his no-holds-barred routines in the 1970s, he recalls his personal struggles after leaving school without any sex education.
The Glasgow-born comic describes himself as a “hopeless nincompoop” when he was 16, who had got his sex education from toilet walls and from “rumours behinds hands.
In tonight’s documentary, he recalls how he was left humiliated at the time when he asked a fellow welder in the Clyde shipyard where he started working about sex and babies.
Billy and Us sees Connolly recall won he won approval from both male and female fans with his graphic descriptions of his efforts with the opposite sex, and also explores how he was one of the first comics to joke about homosexuality at a time when it was “completely unspeakable.”
Connolly says: “When I was young, sex was cloaked in mystery and embarrassment. But as I became a comedian the hairy hippy thing was happening and attitudes were changing and thank God for that.
“Talking about sex then was taboo unless you avoided speaking about anything going into anything. It was okay to speak about as long as you hadn’t got around to it yet.
“I didn’t have any sex education. When I was 16 I was deeply embarrassed. I asked a welder: ‘When you are married do you have sex all the time or do you just have it the once and the babies keep coming?’ He told me to ask another guy,so it would spread.
“I’m one of the people who learned about sex from toilet walls and rumours behind hands.
“When I was 16 I was a hopeless nincompoop. I hadn’t the foggiest idea of what sex was about - except masturbation.”
Exploring his unsuccessful attempts to forge relationships with women as a young man, and how they inspired much of his on-stage material, Connolly said: “I found that making women laugh was easy.
“They laugh easier than men and better and heartier, but getting them from there to being serious about you was an impossibility. I could never read the signals from women. I was lousy at it. They had to fall on top of me before I knew I was there.
“I've always been intrigued by vulnerability. I've always said that when your trousers are down you're vulnerable. Your trousers are usually down for one of two reasons – and one of them is sex.
“Most of my stuff is self-deprecating - I'm the fall guy. I never saw anybody else doing it. But it seemed right with my hippy stance and my other views of the world.
“I was pushing boundaries in whatever I did. It was the way I did it rather than the subject matter, just charging clumsily into it.”
Recalling the changes he had seen in previously hostile attitudes to homosexuality, Connolly said: “Once people were out and they said ‘this is me, live with it’ that all ended and rightly so. It was a pleasure to see it go.”