Every Titanic fan on the planet has been left with one burning question since the credits first rolled 20 years ago: Why didn't Rose move over and make room for Jack on the door?

In a new interview with Vanity Fair in honor of Titanic's 20th anniversary, director James Cameron opens up about why Jack didn't survive the sinking of the ship and his answer is, well, ice cold. "The answer is very simple because it says on page 147 [of the script] that Jack dies," Cameron said. "Very simple.…Obviously it was an artistic choice, the thing was just big enough to hold her, and not big enough to hold him."

"I think it's all kind of silly, really, that we're having this discussion 20 years later," he continued, making it pretty clear that he probably gets asked this question a lot by strangers at bars. Even so, he admits that the sympathy fans still feel for Jack's character, even two decades later, says a lot about the film as a whole.

"It does show that the film was effective in making Jack so endearing to the audience that it hurts them to see him die," said Cameron. "Had he lived, the ending of the film would have been meaningless.…The film is about death and separation; he had to die. So whether it was that, or whether a smoke stack fell on him, he was going down. It's called art, things happen for artistic reasons, not for physics reasons."

But in case you were wondering, Cameron tested the physics of the situation, too, and the door was definitely, without a doubt, only strong enough to hold only Rose. "I was in the water with the piece of wood putting people on it for about two days getting it exactly buoyant enough so that it would support one person with full free-board, meaning that she wasn't immersed at all in the 28 degree water so that she could survive the three hours it took until the rescue ship got there," Cameron told VF. "[Jack] didn't know that she was gonna get picked up by a lifeboat an hour later; he was dead anyway. And we very, very finely tuned it to be exactly what you see in the movie because I believed at the time, and still do, that that's what it would have taken for one person to survive."

Jack, your heart will always go on. But it's time for the rest of us to get over it.

Related: Leonardo DiCaprio and Kate Winslet Quote Their Lines From Titanic to Each Other