Henry Winkler felt "very confused" before he started therapy.

The 81-year-old actor has been in therapy for a decade, and Henry admits that it's changed his outlook.

During an appearance on The Drew Barrymore Show, Henry explained: "I was very confused. I was in my 60s, and I had a birthday. I went and the first thing that the therapist asked me was, 'Oh wait a minute, where are you?' And I had no idea what the woman was saying to me.

"I didn't know how to find [myself]. I didn't know where to look. I didn't even know there was, and slowly but surely -- I explained it that the top of my head was clamped shut like an oil can, like an oil drum.

"Slowly but surely I'm able now to peel it back so that I can let in the universe as opposed to being scared of being right in the universe."

Drew, 51, empathised with Henry's point of view.

The Hollywood star said: "I really appreciate the metaphors that you were using because we go through therapy for years or we go through life for years and we can still have these big giant breakthroughs."

Henry replied: "I love them when it happens.

"I see myself as a chunk of Swiss cheese, so I'm walking around and there are a lot of holes I could fall in, and I'm working to become a chunk of cheddar."

Meanwhile, Henry previously claimed that "luck" has played a major role in his success.

The actor has enjoyed more than 50 years of success in Hollywood, and Henry shared some of the keys to his longevity.

Asked about the secrets to his success, Henry - who shot to international stardom on Happy Days, the hit TV show - told People: "Luck, will, preparation.

"I thought to myself when I was younger, 'You better go to drama school and figure out what the fundamentals are so that no matter what happens when that door opens, you're prepared to walk through it.'"