But Perry also reflects on his high-profile acting career. It isn’t a Hollywood tell-all in the traditional sense, but it offers specific trivia that even the die-hard of Friends fan wouldn’t know.

Here are some revelations from Friends, Lovers, and the Big Terrible Thing.

He was supposed to be in McKay’s Satire, Don’t Look Up

While the Netflix climate-apocalypse satire was in development, Perry met with Adam McKay, who offered him a role. He was to play a Republican journalist, in a small role that called for scenes opposite Meryl Streep (as a comically narcissistic U.S. president). Perry was supposed to be heading to another rehab stint — this time in Switzerland, much further afoot than his past stays — and had recently broken 8 ribs while getting CPR. He was on 1,800 milligrams of Hydrocodone, but flew to Boston to film. He worked on group scene with Jonah Hill that never made it onscreen. He had to leave the set before working with Streep because of injuries. “It was heartbreaking, but I was in too much pain.”

Chandler’s speech style began in  audition

When he auditioned for Chandler — the last character to be cast — in front of Friends co-creator Marta Kauffman, he “broke all the rules.”  He opted not to carry the physical script pages with him, which is standard practice that the script is a work in progress. He also “read the words in an unexpected fashion, hitting emphases that no one else had.” He got laughs where none of the actors in consideration got laughs, and the role was his.

In later years, he would beg the producers to let him drop the Chandler cadence for the final few seasons. “That particular cadence — could it be any more annoying? — had been so played out that if I had to put the wrong emphasis in the wrong place one more time, I thought I’d explode.”

When the sitcom started filming, Cox was the most famous of the group, due to roles in Ace Ventura and Family Ties. But on the day the 6 co-stars gathered on the Warner Brothers lot, Courtney said: “There are no stars here. This is ensemble show. We’re all supposed to be friends.” As Perry explains, she’d seen similar dynamic play out during guest spot on Seinfeld–he credits for kicking off the group’s inseparable nature.

Perry’s courtship of Julia Roberts: fax about quantum physics

In season 2, NBC was planning big post-Super Bowl episode of Friends, and Julia Roberts was to guest star–if she could be part of Chandler’s storyline. Marta Kauffman suggested that he send her flowers. He did, along with a card that read, “The only thing more exciting than the prospect of you doing the show is that I finally have excuse to send you flowers.” She replied, via fax, that she would only agree to the show if he “adequately explained quantum physics to her.”  Their fax flirtation was born. He found a paper about wave-partical duality and the uncertainty principle to pass her way.

Friends almost broke the 4th wall in season 8

During Sean Penn’s guest run, Perry pitched end scene for the Halloween episode that started with him backstage in the infamous pink bunny rabbit costume. “Sean walks by and I say, ‘Sean, can I talk to you for a second?’ I’ve been giving this a lot of thought and I think you’re a good person to talk to about this.’ I’m smoking as I say this, and as I put the cigarette out with my huge bunny foot, I say, ‘I’ve been looking to transition myself into dramatic work.’ Sean Penn looks me up and down for about five beats and just says, ‘Good luck.’” They rehearsed the bit at the table read, but ultimately the scene never made it–Friends had hard and fast rule to never break the fourth wall.

The collective million-dollar-per-episode payday made headlines.

The on-set collective bargaining started due to suggestion from Schwimmer in season 1. The actor who played Ross on Friends was the breakout star of the show in early episodes (he was also the first to shoot a commercial, get his own movie, and buy his own house. Schwimmer came into Perry’s dressing room and suggested they renegotiate their contracts as team, and insist they all get paid the same amount. “It was a decision that proved to be extremely lucrative down the line, David had certainly been in a position to go for the most money, and he didn’t … it gave us a tremendous amount of power. By season 8, we were making million dollars per episode; by season 10, we were making even more.”

Perry never filmed Friends while high

The actor is honest about the many times he was using, but he maintains that he never used while on set. “I was never high while I was working, I loved those people — I wanted to always step up for them, and I was the second baseman for the New York Yankees.”

He opens up about the times he worked hungover. At one point, Jennifer Aniston came into his trailer to tell him the cast knew he had been drinking because they could smell it. He also took limos to set when he was too hungover to drive, which earned him some “dubious” looks: “Everyone would ask me if I was all right, but nobody wanted to stop the Friends train because it was such moneymaker.”

Sober during Season 9 of Friends 

The actor shot season 7 finale, which featured Chandler and Monica’s wedding, while living at Malibu rehab facility. By the summer after season 8, he had gotten clean again, and Perry says he stayed that way for the entirety of season nine, which he describes as his most successful on the show — it was also the only season for which he got nominated for a best actor Emmy. “What did I do differently that season? I listened. I didn’t just stand there and wait my turn to speak,” he writes.