Leonardo Dicaprio finds watching himself in 'Titanic' hilarious.

The 37-year-old actor shot to fame in James Cameron's 1997 epic movie alongside Kate Winslet but the director revealed when he and the Hollywood hunk recently sat down to watch the movie in 3D, Leonardo couldn't stop laughing at how young he looked.

James told Culture magazine: ''When I watch the film now they look like such babies. I sat with Leo in Sydney not long ago and I showed him 18 minutes we had converted. He just couldn't stop laughing at himself as kind of a kid.

''Leo has gotten much more rugged-looking while Kate's beauty has evolved in such a great, striking way. The way I relate to it is that it's a snapshot in time and their characters Jack [Dawson] and Rose [Rose DeWitt Bukater] almost exist as fictional characters independent of who Kate and Leo are.''

James also revealed Leonardo has struggled to leave the role of tragic hero Jack behind him but thinks he has been successful.

He explained: ''I watched from the outside as they struggled to deal with being locked to that iconic film in people's minds, having to take roles to prove they were actors not pop-culture icons.''