NEW YORK--He's Rockin' Robin, Wild Man Williams.
He's the feral child who came from the jungles of stand-up comedy.
He played an extraterrestrial on TV's Mork and Mindy and his wacky style convinced millions he was from another planet.
Through such movies as The World According to Garp, Dead Poets Society, Awakenings and Jack, Hollywood has tried to tame Robin Williams.
Each time the studios thought they had him caged, Williams would sneak in a Good Morning Vietnam, Mrs. Doubtfire or Jumanji, or he'd pop up on another Comic Relief special to prove there are no rules and no limits when it comes to being Robin Williams.
It boggles the mind to think what Williams must have been like as a child growing up in Chicago or a teenager in San Francisco.
Once again, truth is stranger than fiction.
"I was a shy, only child. I was short and chubby and had a difficult time fitting in at school," recalls Williams.
"My father worked in the automobile industry. He was rarely home and when he was, he seemed a bit frightening."
It's Williams' newest comedy, Father's Day, that has him ruminating on his youth, his relationship with his father and his role as a father of three children, including a teenage boy.
"In my youth, salvation turned out to be the wrestling club and track team. I'm still not certain if I was trying to run away from something or just loved running."
In 1969 when Williams was 16, his father retired and moved the small family to San Francisco.
"It was quite a liberating experience and not just because we arrived there at the tail end of the Magic Bus Tour.
"I got to run cross-country through the woods. In Chicago, I'd felt like a hamster running on an indoor track. It sounds corny but in San Francisco, I found inner peace."
And yes, he did sample the drugs that flowed so freely in the hippie quarters of San Francisco.
"There was the time I did mescaline and thought my mother was a lizard, but that's a whole other side of my life I'm not getting into."
Not once during this period was Williams considered the class clown.
"I was in the comedy closet until I went to college. It was there I took my first improv class. Suddenly there was no stopping me. I'd learned what it meant to be completely unrestrained."
Classmates, teachers and audiences at the local comedy clubs immediately sensed Williams' talents and so he was off to New York's Julliard School to study acting.
"I earned money being a mime outside museums in New York. On a good day, I'd make $40 and enough bus tokens and condoms to get me through the week."
Though nothing seems able to mellow Williams the performer, responsibility in the guise of 14-year-old Zachary, seven-year-old Zelda and five-year-old Cody has mellowed Williams the man.
"Zachary is going through his hair period," explains Williams.
"It's been blond, green, black and emerald. Now he's shaved it off. It's like having breakfast with a little marine.
"The other day at breakfast, he asked about getting a tattoo. That proved quite a discussion."
Williams says Zelda is his artistic child.
"She draws and is developing quite a sarcastic wit. It can be scary at times."
And then there's Cody.
"Quality time with Cody is like attending the Jackie Chan day-care centre. It's ninja expression time. That puts Cody and me on an equal temperament level."
In their 1996 year-ender issues both People magazine and Vanity Fair called Robin Williams the funniest man alive.
"Now that's something to have to live up to. They should have just pinned a sign on my butt that reads 'Kick Me'.
"Of course I'm flattered but it's a bit like wearing fibreglass underwear. It's such a strange sensation."
In Ivan Reitman's Father's Day, opening Friday, Williams teams up with longtime friend Billy Crystal to play two men who learn that one of them may have fathered a missing 16-year-old boy.
"Billy and I have been looking for a project to do together for years. We work so well off each other on the Comedy Relief specials that it seemed a natural screen pairing," explains Williams.
"Whenever we're on stage or in front of a camera together, it's like two elk spraying musk.
"It's a healthy competition. It keeps our comedy antlers sharp. Every comic is competitive.
"To deny that is to deny the essence of comedy."