Somebody dosed the cast and crew with PCP.
On the last night of shooting in Nova Scotia, somebody mixed angel dust into the clam chowder. Around 80 people went to the hospital, complaining of hallucinations, crying, and vomiting (James Cameron among them). Frequent Cameron collaborator Bill Paxton told Entertainment Weekly in 1996: "One minute I felt okay, the next minute I felt so anxious I wanted to breathe in a paper bag."
Theaters wore Titanic out.
Titanic's run was so successful, the distributor had to send replacement reels to some theaters because their original copies were going bad from continued overuse.
A home video first.
Titanic was the first major movie ever released on home video while it was still playing in theaters. Yes, it was so popular that it's theatrical run just kept getting extended, even after the movie was available to rent or purchase on the VHS format.
Watch the clock.
In one of the film's cool historical touches, the clock behind Jack in the movie's final scene reads 2:20 a.m.. That's the exact time the ship sank that night in April 1912.
There was a real J. Dawson on the Titanic.
Titanic of course is a fictionalized tale set during the very real sinking of the RMS Titanic, but unbeknownst to James Cameron when he was making it, there was a real person named "J. Dawson" onboard who died during the tragedy. It was Joseph Dawson, not Jack Dawson, but fans of the movie often visit his grave nonetheless.
No, there wasn't room for Jack.
Cameron is fed up with people trolling his film by insisting Rose could've moved over and made room for Jack on that piece of flotsam and jetsam, thereby saving his life. "I think it's all kinds of silly, really, that we're having this discussion 20 years later," he groused to Vanity Fair in 2017. "Obviously, it was an artistic choice." That piece of wood paneling was based on an actual artifact from the Titanic, a piece of history that's on display at the Maritime Museum of the Atlantic in Nova Scotia. Over 20 years later, Titanic remains a king of references. Jokingly, reverently, sarcastically, self-deprecatingly: however we've done it, many of us have stood at the edge of a boat or car or balcony and shouted, "I'm the King of the World!" Around the time of Titanic's 3D re-release in 2012, the now defunct Gawker website compiled a super cut of 50 different instances of this in pop culture. This included scenes from The Simpsons, Saturday Night Live, Modern Family, and The Office. A must mention is the awesomely bonkers moment in 1999's "Oops!... I Did it Again" when Ms. Britney stops the music to make a reference to the "Heart of the Ocean."