As Tom Hanks‘ titular simpleton says in Forrest Gump, “My mama always told me that miracles happen every day. Some people don’t think so, but they do.” As if to prove the point, director Robert Zemeckis recalls, “It was a miracle this film got made. The executives didn’t know what this was — they didn’t see it as a viable movie.”

A whimsical, historical comedy-drama based on a little-known novel, Forrest Gump was the ultimate cinematic underdog. But like its main character, the movie went the distance, earning $677 million worldwide and winning Oscars for best picture, director, actor, screenplay, editing and visual effects. Not bad considering “we weren’t even given the money in the budget to make a crew T-shirt,” says Zemeckis. Adds Tom, “That’s how little faith the studio had in us!”

Tom Hanks in 'Forrest Gump'
Paramount/Getty Images

Twenty-five years after its initial release, Forrest Gump remains a beloved favorite, with a new Blu-ray Disc having just been released. “It’s a timeless movie,” producer Wendy Finerman exclusively tells Closer Weekly in the magazine’s latest issue, on newsstands now. “It presents Americans in a really positive way.”

Even after Paramount reluctantly green-lit the project, getting Forrest Gump made was no easy task. The film shot during the summer in South Carolina and Georgia. “It was really sweltering and humid,” production designer Rick Carter recalls to Closer. “There were alligators and water moccasins in the water for the Vietnam scenes.”

Making Forrest’s far-fetched feats look believable was a challenge as well. “As great an actor as Tom is, he’s not as good a pingpong player as Forrest is,” says Zemeckis. “We had the actors mime playing pingpong and put the ball in later optically. Of course, in typical movie fashion, we hired the greatest pingpong player in the world to be his opponent, but the guy had never played without a ball before.” Remembers Tom, “He had such a tough time. It was exhausting!”

Mastering Forrest’s Southern accent also proved difficult for Tom — until 8-year-old Michael Conner Humphreys was cast as the younger version of his character. “Me and Tom spent a lot of time together,” says Michael, who later served in the Army in Iraq. “I guess he was trying to feed off me and get an idea for the character. I was a natural Southern kid.” Notes Tom, “He had this voice that seemed to come out of his backbone, so it was taking the way his vocal cadences are and making him grow up a little bit.”

Tom Hanks with an Oscar
John Barr/Liaison

A rambunctious kid, Michael admits, “I was hard to control.” Good thing, then, that Sally Field played his mother. As Finerman points out, “She had been a child actor, and she knew what he needed as a mother and a fine, fine, Academy Award–winning actress.”

In the end, the entire cast and crew pulled together to make an enduring classic. But don’t expect a sequel. “We’re all very protective of Forrest Gump,” Finerman says. “We were all so happy with the outcome. There’s something to be said for just letting it be.” Mama couldn’t have said it better herself.

For more on your favorite celebs, pick up the latest issue of Closer Weekly, on newsstands now — and be sure to sign up for our newsletter for more exclusive news!