Why John Stamos "Hated" Ex Rebecca Romijn During "Painful" Divorce

John Stamos is looking back on his relationship with ex-wife Rebecca Romijn with a little more mercy these days.

The Full House alum admitted that it was "really difficult" to detail their marriage in his upcoming memoir If You Would Have Told Me because it opened his eyes on the skewed view he had of the X-Men star during their separation.

"My first marriage was shattering to me. I was shattered for way too long, too," Stamos told People in an interview published Oct. 18. "In my mind back then, she was the Devil, and I just hated her."

The 60-year-old continued, "I couldn't believe how much I hated her, and it ruined my life. Looking back, and I talk about it [in the book], because it's one of the steps in AA where the fourth step is you lay out all your grievances, everything that people did to you. I go like, 'None.'"

Stamos now recognizes how he played "some part" in the collapse of their marriage, acknowledging that Romijn, 50, "was trying to make it work because she cared" about him before their split.

"You start thinking, it's like, 'Oh, she wasn't the Devil. Maybe I was as much to blame as her,'" he shared, going on to note that their divorce was "very public" and "very painful." 

"It was very much the opinion that she dumped me because her career was going great and mine wasn't, and that's humiliating," Stamos added. "I don't blame her for it. It was just the perception that people took, and maybe they weren't wrong. She was doing great at that time and I wasn't."

Stamos and Romijn were married for nearly six years before calling it quits in 2004. 

Since their divorce was finalized in 2005, both parties have moved on to new romances. Stamos is now married to Caitlin McHugh Stamos, with whom he shares 5-year-old son Billy, while Romijn is mom to twin daughters Dolly and Charlie, 13, with husband Jerry O'Connell.

For Romijn, the breakup was equally difficult. "Going through a divorce is terrible, it's awful," she shared on The Talk last year. "Divorce feels like a failure and there were a lot of things that I had to let go of that were very sad."

Reflecting on the struggles he endured in the aftermath of split, including an addiction to alcohol, Stamos told People, "Without that, I never would've known what a real love is, and I would've never straightened up to get someone like Caitlin in my life."

"If I didn't go through all the things, all the heartache," he said, "I wouldn't be who I am today."

E! News has reached out to Romijn's rep for comment but hasn't heard back.

To see Stamos' family photos, keep reading.

John and Billy appear in a video the actor posted on his 60th birthday.

John Stamos and Caitlin McHugh brought their son Billy Stamos to Disney Junior's "Glow Webs Glow" event celebrating the second season of Marvel's Spidey and His Amazing Friends in August 2022.

The duo rocked serious looks during their trip to NYC in December 2022. 

"UFO welcoming committee," Stamos captioned a photo of him and Billy posing with Iron Man in July. 

Billy paid Stamos a visit on the set of his Disney+ series Big Shot.

The father-son pair snuggled at cruising altitude in this pic that was shared in mid-July.

Stamos and McHugh hold Billy and celebrate the Fourth of July.

The actor posts a photo of himself gardening with Billy. 

The People's Choice Awards winner starts off 2019 by posting this precious father-son photo to Instagram.

The Stamos trio donned matching outfits and Santa hats in this adorable pic that's perfect for their 2018 Christmas card.

"Already my favorite Christmas," Stamos captioned a photo of him and his son spending the holiday season at Disney.

While Billy may be too young to vote, the Grandfathered actor encouraged everyone to get out and vote during the 2018 midterms.

In October 2018, the California native took a dip with his son in the pool.

The ER alum is caught leaning over to give his son a kiss on Billy's first Fourth of July.

McHugh snapped this adorable pic of her husband and son on her birthday writing, "I'm the luckiest birthday girl in the world to spend today with you two."

Stamos went from everyone's favorite fictional uncle to real-life dad in April 2018 when his and wife Caitlin McHugh's son Billy was born. The sitcom star introduced little Billy to his Full House co-stars Bob Saget and Lori Laughlin.