Shortly before his death, Garry Marshall opened up to PEOPLE about the longstanding friendships in his life
Credit: Lee Celano/WireImage

Garry Marshall was one of the most beloved luminaries in Hollywood – as evidenced by the number of celebrities who are mourning his death Tuesday at 81. But the writer and director’s last interview with PEOPLE reveals just how important his personal relationships were to his success, and paint a picture of a loving grandfather and friend as well as an acclaimed Hollywood hitmaker.

Speaking before the premiere of his last film, Mother’s Day, earlier this year, Marshall explained how his longstanding relationships with stars including Julia Roberts made casting easy.

“Why I get along with them is I don’t call them, I bump into them,” he told PEOPLE, calling his strategy “the key to movies.”

“Julia Roberts has a 10-year-old and I have a 10-year-old grandson,” he also said. “They play in the same little league, so there I am in the stands, cheering with Julia, and eventually between innings she’ll say, ‘What are you doing?’ ‘I’m doing Mother’s Day – You’re a mother!’ ‘Yeah? Okay.’ ”

He went on to joke that he’d visit Roberts’s Malibu house with a script “and shove it in her mailbox.”

“She reads it, goes ‘Okay, I could do something’ and she picks her part and that’s it,” he said. “That’s not usually the way show business works.”

Roberts wasn’t the only longtime friend Marshall turned to for Mother’s Day. He also cast Kate Hudson, whom he had previously worked with on Raising Helen. He first met the 37-year-old when she was 7½, on the set of mom Goldie Hawn‘s movie Overboard.

“It may sound corny, but I’m a corny guy,” Marshall said. “When I was doing Overboard, I would hold Kate Hudson in my lap and I’d say ‘Let’s yell ‘Action!’ for mommy! Look, mommy’s funny!’ So in this movie, I had her two sons there sitting in my director’s chair. ‘Here she comes – watch mommy, she’s going to be funny.’ So it was a circle.”

Connecting circles was important to Marshall. He cast Chris Pine in The Princess Diaries 2: Royal Engagement, and Chris’s father, Robert Pine, in Mother’s Day. That relationship made Marshall feel confident Pine would return for another Princess Diaries installment.

Chris Pine likes me, you know why? Because his father is in Mother’s Day!” he joked. “His father I know, I’ve seen him in plays. Chris Pine and my kids went to similar schools, so I knew him as a kid.”

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Marshall’s warmth was evident on his sets, which he described as being “open” to everyone’s family. “I always meet everybody’s parents, and like kids to be running around,” he explained. “I love when they come to the set and say hello.”

For Mother’s Day – a “feel-good movie” meant to “salute mothers” for all they do – his set seemed particularly full.

“The kids were there,’ he said. “I had all my grandchildren there. Kate Hudson’s kids were there, Julia’s kids were there, Jason Sudeikis had his son there – it was quite that kind of set. I love the kids – they make me laugh.”

Judging by the love Marshall’s been receiving after his death, the feeling appears to be mutual.

Reporting by KARA WARNER