Leonardo DiCaprio's Titanic role was nearly played by Paul Rudd

The actor originally auditioned to play the role of the plucky, charming Jack Dawson in James Cameron's 1997 blockbuster

There's an alternate timeline right now in which Paul Rudd just won an Oscar for The Revenant.

Teen heartthrob-era Rudd originally auditioned for the role of Jack Dawson in James Cameron's 1997 blockbuster, Titanic; the role which was eventually so famously played by Leonardo DiCaprio. This was in the time before Rudd first dipped his toe in comedy, coincidentally starring opposite DiCaprio's Romeo in Baz Luhrmann's 1996 Romeo + Juliet, playing spurned suitor Dave Paris.

But what's even more interesting is the reason Rudd was so keen to get involved in the production. "My dad was a Titanic historian, that's what he did for a living," he told James Corden on The Late Late Show. "He used to take people all over the world talking about the Titanic."

Which would have made for an adorable backstory if he had landed the role, except his inherited nerdom about the ship actually proved less endearing to casting directors. "I knew so much about the ship. I went into the audition talking about the kind of steel that was used and Harland and Wolff, where they built it," he recalled. "And they were like, 'OK... none of this matters.'"

He joked, "I think the guy that got it was pretty good,"; before recreating the iconic, "I'm the king of the world!", moment with the help of Diane Lane.

While alternate timeline Paul Rudd is off polishing his Academy Award somewhere; our own timeline's Paul Rudd is set to reprise his role as Ant-Man in Captain America: Civil War, which hits UK cinemas 29 April.