The actor also spoke about having crushes on his female "Friends" co-stars, including Jennifer Aniston.
After many years of struggling with addiction and amid his sobriety journey, Matthew Perry is revealing how people will know if he's relapsed.
During a sit-down interview with Diane Sawyer on ABC News, which aired on Friday, the actor -- who was promoting his upcoming memoir, "Friends, Lovers, and the Big Terrible Thing" -- opened up about his battle with drug and alcohol addiction, including the warning signs that will tell people he's in "trouble."
"How will we know when you're in trouble, when you're not okay?" Sawyer asked Perry, who replied, "If I say, 'I'm just going to chill at home alone tonight.' And part two, the other thing, is if I ever say, 'I'm cured.'"
The "Friends" alum -- who details his struggles with addiction in his memoir -- has revealed that throughout his life, he's attended 6,000 AA meetings, went to 30 years of therapy and has had 15 stints in rehab. As Sawyer noted, Perry said he's spent "at least half of [his] life in treatment or in sober living houses," has detoxed approximately 65 times and has "survived 14 surgeries."
Recalling how his addiction first started, the 53-year-old said he had his first drink when he was 14.
"I had never drank before," Perry told Sawyer, revealing he consumed an "entire bottle" of wine. "And I lay in the grass and was in heaven. I thought to myself, 'This must be the way normal people feel all the time.' ... By the time I was 18 I was drinking every day."
He was cast as Chandler in "Friends" at the age of 24 -- and his struggles with alcohol continued. And just how he can recall having his first drink, Perry said he remembers taking his first pain pill. While shooting the 1997 rom-com, "Fools Rush In," he got into a jet ski accident and was prescribed a painkiller. This ignited his drug addiction.
Perry built up a tolerance to the point where he was taking 55 Vicodin a day. "I had to wake up and realize I needed to get 55 of them or I was going to be really sick. A bunch of doctors, fake migraines," he told Sawyer. "I guess the weirdest thing I did was on Sundays I would go to open houses and go to the bathrooms in the open house and see what pills they had in there and steal them."
Perry added, "I think they thought, 'Well, there's no way that Chandler came in and stole from us.'"
During his conversation with Sawyer, he went on to detail suffering from addiction while starring in "Friends," noting that he always tried to put the sitcom first, no matter what.
"I made a rule that I would never drink or take anything at work," Perry said. "So I would never do that, but I would show up blindly hungover. Like shaking."
"I loved Chandler, I loved the show," he added. "And I knew, 'Remember this, because it's going to be the best time of your life.' And I knew I would never forgive myself if I messed this up."
On a lighter note, Perry also spoke about his past crushes on his "Friends" co-stars, including Jennifer Aniston, whom he knew before he joined the sitcom. He said he had asked her out on a date, but she turned him down. However, Perry said Aniston told him they should just be friends.
Although they were just pals, Sawyer noted how Perry wrote in his book about seeing Aniston on set, asking "how long" could he look at her.
"I was like, 'Is three seconds too long? How long is…?'" he recalled to Sawyer. "And then I write in the gratitude part [of the book] about her letting me do that."