United Kingdom, Sept. 10 -- Henry Winkler finally started therapy aged 70 to rid himself of "rancid garbage" in his mind.

The Happy Days legend, now 80, started speaking to a professional around a decade ago after realising he was struggling to think rationally.

Admitting he felt like he was "treading water", he told In Depth With Graham Bensinger: "About 10 years ago, maybe 12 years ago, I was pretty good at either figuring things out or making it or smoothing things out in my mind or rationalising.

"And I just couldn't do it anymore."

His wife Stacey Weitzman previously admitted she wasn't being "let in", and the actor confessed he "didn't let anybody in".

He added: "I was not being able to just [say], 'Oh, well, OK, I'll move that...