It’s A Wonderful Life may have been a box office flop when it first came out way back in 1946, but in the decades since then, it has become a beloved Christmas classic that is enjoyed by millions of fans to this day. That’s why we decided to compile five surprising facts about the Christmas movie that you’ve likely never heard before.

Uncle Billy Scene

You might remember that in the scene in which Uncle Billy leaves the Bailey home, it sounds as if he stumbles into some trashcans outside on the sidewalk. What you may not know, however, is that a member of the crew had dropped a large tray of props right after he went off-screen. This caused star James Stewart to burst out laughing, and Thomas Mitchum, the actor playing Uncle Billy, quickly improvised “I’m alright, I’m okay!”

Director Frank Capra decided to leave this moment in the final cut of the film, and he liked it so much that he gave the stagehand a $10 bonus for “improving the sound.”

The Emotional Bar Praying Scene

Stewart later said that in the scene in which his character of George Bailey prays in the bar, he was so overcome with emotion that he began to sob. Capra later re-framed and blew up the shot because he wanted to catch that expression on Stewart’s face. This is why you may notice that it looks so grainy compared to the rest of the movie.

It Was Filmed In A Heat Wave

Though It’s A Wonderful Life is a Christmas movie, it was actually filmed during a heat wave. In fact, the weather eventually became so hot that Capra gave everyone a day off to recuperate. The scene in which Clarence saves George on the bridge was filmed on a back lot on a day where the temperature was 90 degrees Fahrenheit. That’s why you might notice that Stewart is visibly sweating in some scenes.

Two Of The Writers Despised The Movie

While the film is beloved today, two of the writers hated the final version so much that they called it “horrid” and refused to even see it once it was released.

Only Film In History To…

It’s A Wonderful Life is believed to be the only movie to ever originate from a greeting card. The film was based on a “Christmas Card” short story by Philip Van Doren Stern, which was originally sent out to around 200 of his family and friends in December of 1943. Inspired by a dream Stern had one night, the short story was called “The Greatest Gift.”

Find out more surprising facts about this movie in the video below!