“When you sneeze the reason people say bless you is because your soul momentarily leaves your body and if someone says bless you it makes your soul go back in.”
Context: I collected this story from Reed at the University of Southern California. Reed is an American Jew with roots in Louisiana. He heard it for the first time when he was a kid and heard it numerous times since.
Analysis: I have heard this story a number of times and have heard a number of variations. One theory that was discussed in my folklore class is that sneezing is a signifier of getting sick, which is an element that people have no control over. This is why they continue to pass on the story. Another variation is that your heart stops when you sneeze and you have to say “bless you” because you actually died momentarily.