Steven Spielberg pulled off one of the greatest cinematic achievements in history upon releasing both the global blockbuster hit Jurassic Park and his eventual best picture winner Schindler’s List in 1993. While the feat solidified Spielberg’s rightful position as one of the most respected filmmakers in history, the weighty undertaking of crafting two ambitious projects at the same time took a substantial emotional toll on the director.

“It was the best draft [Schindler’s List writer Steven Zaillian] had written after [writing] multiple drafts,” Spielberg told the crowd Thursday evening at the Tribeca Film Festival’s 25th anniversary screening of the movie in New York City. “[So my wife] Kate said, ‘You’re making this movie right now, aren’t you?’ And I said, ‘Yeah, right now!'”

There was a significant conflict when he set out to make the esteemed holocaust drama, however: “I was making Jurassic Park right now,” he continued. “That was the problem. [But] I didn’t want to miss the winter. I knew I had to be shooting [Schindler’ List] in January [on location] in Poland, so it came together awfully quickly.”

Image zoom Jamie McCarthy/Getty Images for Tribeca Film Festival

By the time Spielberg had assembled his cast and crew — including Liam Neeson, Embeth Davidtz, Sir Ben Kingsley, and Caroline Goodall, all of whom were also present at the reunion panel — he was deep into production on Jurassic Park.

“When I finally started shooting…in Poland, I had to go home about two or three times a week and get on a very crude satellite feed to Northern California…to be able to approve T-Rex shots,” he remembered. “And it built a tremendous amount of resentment and anger that I had to do this, that I had to actually go from [the emotional weight of Schindler’s List] to dinosaurs chasing jeeps, and all I could express was how angry that made me at the time. I was grateful later in June, though, but until then it was a burden.”

The work paid off, however, as Jurassic Park banked over $1 billion at the worldwide box office and Schindler’s List went on to claim seven Oscars — including the first of Spielberg’s two best director trophies (he’d claim the other for helming Saving Private Ryan six years later).

“That night wasn’t really a celebration at all. I don’t feel that this movie is a celebration,” he said of the 1994 Academy Awards ceremony. “The subject matter and the impact the movie had on all of us…it took the celebration out of that. It was wonderful to win, but at the same time I just remember how moved I was when [Branko] Lustig, our producer, showed the world that he was in Auschwitz, too, that he had numbers on his arm.”

Lustig memorably discussed his Holocaust experience during the Oscars telecast upon Schindler’s List claiming the best picture prize.