Billy Joel was "devastated" by his split from Christie Brinkley

He said in his HBO documentary Billy Joel: And So It Goes: "Here I am dating this beautiful supermodel and ... me? I'm from Hicksville. What am I doing with her? What's she doing with me? But that was a very productive time for me. I wrote a lot of songs for her. She was a muse.

"It was like being a teenager all over again. Experiencing those same emotions that I had when I was first discovering romance and love."

Bill remembers the first few years of their romance being "so much fun".

However, Billy admits that his music career and the stresses of fame took a toll on their relationship.

He said: "I was in a relationship with someone who I cared deeply about. But I was not able to be at home. I was not able to be with my family. It was a very sad time for me.

"I realised love is not concrete. You feel like it is, but there are things eating away at it. And in the end, it all catches up. It's hard. I was so devastated."

Meanwhile, Billy has admitted to being given an ultimatum by Katie Lee, his then-wife, before he entered rehab in 2005.

The musician checked into the Betty Ford Center for the treatment of alcohol abuse, after Katie instructed him to either seek help or end their relationship.

He said: "With the rehab, you don't go for somebody else. You have to go for yourself. You have to want to do it. I didn't want to do it."

Katie - who was married to Billy between 2004 and 2009 - noted that the music star struggled with addiction after taking a break from the spotlight.

She explained: "I felt like he needed to be creating, he needed to be making music, performing, to turn down that anxiety of not having an artistic outlet. And there were struggles with addiction. It was really hard to navigate that, because I had no experience with it."