Getting through breakups and divorce is hard and no celebrity is immune to it. Hollywood star Ashton Kutcher has revealed that he had run to the mountains to get over his divorce from Demi Moore in 2013.

The 40-year-old star revealed surprising new details about how he got over Moore as he sat down to chat with actor Dax Shepard on his Armchair Expert podcast.

Kutcher said: "Right after I got divorced, I went to the mountains for a week by myself. I went into Big Sky in Montana, and I did no food, no drink — just water and tea."

He continued: "I took all my computers away, my phone, my everything. I was there by myself so there was no talking, and I just had a notepad and a pen and water and tea for a week." The That 70s Show actor explained that during his seven-day "spiritual" visit to Big Sky, Montana, his liquid diet began to catch up with him.

"I started to hallucinate on like day 2 which was fantastic. It was pretty wonderful. I was doing tai chi with my own energy," Kutcher joked. He revealed that he practised Tai Chi as part of self cleansing, although he has no training in the martial art form. "I was just doing what came to me," he said.

Kutcher's divorce from Moore was settled in 2013 — two years after the couple were separated.

As part of his moving on, Ashton spent his week-long fast writing down all his regrets in past relationships. He recalled: "I wrote down every single relationship that I had where I felt like there was some grudge or some anything and then I wrote letters to every single person and sent the letters on day 7. I typed them all out and sent them."

Kutcher didn't say how the letters were received by his exes, but he did say he found the experience cathartic. "It was almost like an A.A. exercise, where I was like, 'I probably have done some damage,' so I just cleared [my] palate."

The actor said his retreat was "really spiritual and kind of awesome" to his friend Shepard in his podcast.

Moore and Kutcher got married in 2005 and they split up six years late. Each released separate statements, with Kutcher saying, "I will forever cherish the time I spent with Demi. Marriage is one of the most difficult things in the world and unfortunately sometimes they fail."

Moore said in her statement, "It is with great sadness and a heavy heart that I have decided to end my six-year marriage to Ashton. As a woman, a mother and a wife there are certain values and vows that I hold sacred, and it is in this spirit that I have chosen to move forward with my life."

Kutcher went on to marry Mila Kunis in 2015. They have two children together — a daughter named Wyatt Isabelle, 3, and a 1-year-old son Dimitri Portwood.