Henry Winkler felt "so dumb" to have turned down the part of Danny Zuko in 'Grease'.

The 77-year-old actor was best known for playing The Fonz in classic sitcom 'Happy Days' when he was offered the part of high school student Danny - which eventually went to John Travolta - in the 1978 movie musical and admitted he had "so many sleepless nights" worrying about being typecast.

In an excerpt from his upcoming memoir 'Being Henry: The Fonz and Beyond'': "I was dumb. I spent so much energy, so much time - I spent so many sleepless nights thinking, how do I not get typecast? You go with the flow. What you do is you prepare to reinvent yourself. You do something completely different and then come back to center. "

The Emmy Award-winning star went on to add that he had spent "most of his adult life being frighted" but as he reflects on the years gone by now he has come to the conclusion that he must be "grateful" for the opportunities that have been presented to him.

He added: "I spent most of my adult life being frightened, on the outside looking like I had it together and mostly being anxious. The biggest lesson, I really now believe today in 2023 looking back, is not only must you be tenacious, not only must you be grateful, but you also have to be flexible.

"You have to take a leap of faith. You have to jump off the precipice and just trust you're going to fly, because there were so many years I was not hired as an actor. I have a family, I have a house. What am I going to do? And then somebody suggested I become a producer. I start off saying, 'I can't do it. I'm dyslexic. I have no idea what the business is. I can't do it.' And then finally you say, 'Oh, just shut up and try.

"So I think 'shut up and try' might be the most important lesson that I could pass on to somebody."