"Titanic was very much an experiment for Kate Winslet and I," he said.
"We'd done all of these independent movies. I loved her as an actress and she said, 'Let's do this together, we can do this.' We did it, and it became something that we could've never foreseen."
The current Oscar frontrunner admitted that after the success of the film, the level of fame he achieved seemingly overnight surprised him, reported People magazine.
"People said, 'Do you realize how big of a movie this is?' I said, 'Yeah, it's big. It's a big movie.' They're like, 'No. No. No, it's the biggest movie ever,' and I'm like, 'Well, what does that mean? So it's big'.