Harold Ramis had a hand in creating some of the most beloved and quotable films of a generation. When news of his death began to spread on Monday, millions mourned the loss of such a creative genius, and every social media outlet was flooded with memes, artwork, and quotes in remembrance of Ramis. But over the years, as much as we came to feel like we all knew him through his work, there was a lot that many didn’t know, and that includes the difficult battle he had with fellow Ghostbuster Bill Murray.

During the filming of “Groundhog Day”–one of the duo’s most revered films–Ramis and Murray disagreed heavily on what the tone of the story should be, and it caused a great deal of friction between the friends. While Murray wanted the tale to lean towards the philosophical, Ramis wanted to hold on to his comedic roots and keep things light. The result, Ramis said in an interview, was a disaster behind the scenes.

“At times, Bill was just really irrationally mean and unavailable; he was constantly late on set,” Ramis told The New Yorker in 2004. “What I’d want to say to him is just what we tell our children: ‘You don’t have to throw tantrums to get what you want. Just say what you want.’”

At that time, the two hadn’t spoken in eleven years. In the interview, it clearly pained Ramis to talk about the gulf that separated them, but there was one thing standing in the way of a reconciliation.

“It’s a huge hole in my life, but there are so many pride issues about reaching out. Bill would give you his kidney if you needed it, but he wouldn’t necessarily return your phone calls,” Ramis said.

But no matter what happened between the friends, Ramis remained a passionate supporter of Murray’s work and said he was grateful for the projects they’d had the chance to work on together.

“Bill was a strong man…You’d do a movie with Bill, a big comedy in those early days, just knowing he could save the day no matter how bad the script was, that we’d find something through improvisation,” Ramis said. “That was our alliance, kind of, our big bond. I could help him be the best funny Bill Murray he could be, and I think he appreciated that then. And I don’t know where that went, but it’s there on film. So whatever happens between us in the future, at least we have those expressions.”