When I was a child, the Scholastic Book Services would come into class every couple of months and hand out catalogs from which we could order books. One book that was in almost every catalog was
Strangely Enough! by Carroll B. Colby. It was my introduction to such things as haunted houses, mysterious disappearances of human beings, spontaneous human combustion, Airships of 1897, etc. When you consider that at the time I was unaware that anyone anywhere had actually claimed to have even seen a ghost, you can imagine how it freaked me out.
Anyway, one of the freakier stories was called "The Man Who Fell Forever." It was about a sailor named Curley who loved high places and who often wondered how it would feel to fall from some dizzying height. Whenever they had shore leave, his fellow sailors would urge him to climb higher and higher obstacles. Finally, somewhere in South America, they came upon an rickety abandoned lighthouse. They bet that Curley couldn't reach the top of the decaying structure. Naturally he took up the challenge, and a neutral observer was sent up with him to witness his success or lack thereof.
Well, Curley (and his second) reached the balcony around the lamp area, but their voices didn't reach the others, who were playing cards far below. The second man said they might as well start down the rickety staircase. But Curley suddenly yelled "I know a quicker way!" and jumped over the railing.
The second man ran to the edge, but there was no sign of Curley down below, and the sailors still serenely played cards. When the witness finally picked his way down, his fellows denied that Curley had landed (he should have dropped right amongst them). The sailors searched the buildings, the grounds, the dunes, the beach, and the edge of the ocean, but Curley was never seen again. He had disappeared on the way down.
And, of course this story was 100% TRUE!
I wonder if the opening poster heard some version of this story as a kid. When I were lad, kids told stories to each other on the playground and at Grandma's house all the time, including tales adapted from Colby, because a) there was no Internet, b) there were no computer games, and c) almost every schoolchild I knew had access to this book in particular and stole from it.
It stood out to me, at least, more than any other "falling" story would, because it was one thing to know that if you fell you'd hit the earth and probably die -- that was an unfortunate fact of life -- but to fall
and just keep falling -- that was pretty freaky.
The newspaper strip
L'il Abner around the same era didn't help. There was a "Bottomless Canyon" near Dawgpatch, and Abner was explaining to a city-slicker (who was paranoid about falling in and leaving a bloody mess) that he didn't have to worry about
hitting. "You'd jes' fall and fall, until you died, and after your body shriveled and dried out, you'd jes' float, like a dead leaf."