Guardians of the Galaxy director James Gunn says Disney "totally had the right" to fire him over decade-old tweets that joked about rape and abuse.
He was rehired to direct the third instalment of the Marvel franchise in March, after the film's stars signed an open letter asking for his return.
Gunn says he "feels bad" about some of the ways he's spoken in public in the past and "some of the jokes I made".
"I feel bad for that and take full responsibility," he told Deadline.
Gunn was fired in July over tweets that Disney described as "indefensible".
He apologised at the time and said he took full responsibility.
But 10 days after he was fired, Bradley Cooper, Chris Pratt, Zoe Saldana, Karen Gillan, Vin Diesel and Dave Bautista - who all star in Guardians - signed an open letter saying they supported the director.
"In casting each of us to help him tell the story of misfits who find redemption, he changed our lives forever. We believe the theme of redemption has never been more relevant than now," they wrote.
Speaking in his first interview since being fired and then rehired, Gunn called the day he was kicked off Guardians the "most intense" of his life.
"There have been other difficult days in my life, from the time I got sober when I was younger, to the death of friends who committed suicide.
"But this was incredibly intense. It happened, and suddenly it seemed like everything was gone. I just knew, in a moment that happened incredibly quickly, I had been fired.
"It felt as if my career was over."
But the director, who already had a script ready for the third Guardians, says being sacked by Disney also made him feel love "for the first time".
"From my girlfriend Jen, my producer and my agents, Chris Pratt calling me and freaking out, Zoe Saldana and Karen Gillan, all calling and crying.
"That amount of love that I felt from my friends, my family, and the people in the community was absolutely overwhelming.
"So a part of that day was the worst of my life, and a part of it was the greatest day of my life."
He says that "people have to be able to learn from mistakes".
"If we take away the possibility for someone to learn and become a better person, I'm not sure what we are left with."
The Guardians of the Galaxy films grossed more than £1.2bn, according to Box Office Mojo, and Gunn says he got "a little bit teary-eyed" when he was asked to return for Volume 3.
He says Disney co-chairman Alan Horn asked him to come back because "he thought that was the right thing to do".
"I was touched by his compassion."
Gunn says not being able to complete the story of Rocket, played by Bradley Cooper, was one of the things he felt saddest about when he thought he wouldn't get to direct the third Guardians.
The lovable raccoon's character has developed significantly since the first film, with him taking on a much larger role in the latest Avenger's movie, and Gunn says that arc is set to be finished in the next movie.
Before that though is DC's next Suicide Squad film, which he was hired to write after leaving Guardians.
"I don't think I've had as much fun writing a script since maybe Dawn of the Dead. That's what this whole movie has been like."