Nowadays, depending on who you ask, some might argue there's no such thing as too many superhero movies -- Superman movies in particular. But back in the day (i.e. the 1970s), when mainstream superhero entertainment culture was far less prominent, they were perceived very differently. While some fans would do anything to watch Henry Cavill wear the cape as Kal-El and save Metropolis again, there was a time when the uncertainty surrounding the success of a Superman film was apparent. Specifically, Christopher Reeve, the late actor known for playing the third live-action Superman (Kirk Alyn and George Reeves portrayed the Man of Steel before him), wasn't convinced 1978's "Superman" would be a success. It took, quite literally, thousands of screaming fans to persuade him that the movie would work.

In "Still Me," the actor's 1999 autobiography, which presents Reeve's experience as the big screen Superman and details his life-altering injury during an equestrian competition, the actor shared the moment he knew his first Superman movie was going to be loved.

Is It A Bird? A Plane?

In the book, Christopher Reeve writes about one of the scenes in the film where Superman captures a burglar climbing up a building and brings him down to the street. To film the scene, Reeve waited until his crew was ready and was sent to the set with multiple bodyguards.

The movie's director, Richard Donner, was concerned about Reeve's safety. When the actor arrived to shoot the scene, not a single fan was in sight on the busy streets of New York — which had Reeve convinced the film would be a "flop." However, when he walked through a passage to the front of the building where the "Superman" crew was filming, the actor spotted thousands of fans "jamming" the sidewalks on both sides of the street. Cranes, harnesses, and wires hooked Reeve to safety, and when he was hoisted up mid-air, fans cheered and applauded, paying no attention to the large number of crew members or the harnesses in sight. It was magical to see Superman in costume and in action — and as Reeve describes it, he knew at that moment that "Superman" was going to be very, very loved.

'That's When I Knew'

Hear the story from Christopher Reeve in his own words, as he writes in his autobiography:

"Finally they were ready to shoot, and I came out of my trailer with my two guardians. There was nobody there -- absolutely no one in sight. I thought: We're a flop. Nobody cares. We walked through a passageway to the front of the building on 57th Street. As I came around the corner, I suddenly saw several thousand people jamming the sidewalks on both sides of the street. When the crowd spotted me in the Superman costume, a huge cheer went up. I was stunned, relieved, and suddenly quite nervous."

Reeve's nervousness quickly disappeared when he received a roaring approval from fans who stood by to watch. They didn't care that Superman was held up by harnesses — they believed in him and thought it was incredible anyway:

"The wires were lowered from the construction crane. I shook hands with the burglar and was hooked up to the harness underneath my costume. [Richard] Donner called for a rehearsal. I double-checked that the hooks were closed and locked, then gave the thumbs-up to indicate that I was ready. As I was hoisted up, the crowd roared their approval. They didn't care about the crane or the wires; they were willing to look past all of it. There was Superman, flying up the side of the building. That's when I knew the movie would work."

Since Reeve's Superman film and its sequels, multiple actors have worn the cape on the silver and small screens. From Tom Welling to Henry Cavill to Tyler Hoechlin, and many that came before and after, the hero remains widely beloved, whatever medium fans may have met him through: movies, television, or comic books.

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