What made people think that a cat has nine lives?

The saying "cats have nine lives" is an old folklore myth, a saying that has been passed down for generations along with other superstititions like throwing salt over your left shoulder if you spill it. The saying originated when people noticed cats lived through situations that would kill a dog or a human, such as falling from a couple stories up out of a tree or escaping the reach of a predator about to kill it. It was assumed by people that the cat had actually died when it fell from the tree (anything else would have broken its neck), but because it had "extra" lives it could get back up and walk on. The real answer is cats are extremely flexible and agile and are able to arrange themselves to take the least amount of hurt from things like falls from height, and are able to escape through very small openings such as a hole in a fence.