When I was a little girl, about four years old, my sister Lizzy and I had this book of children's poems. I think it was called "Oh What a Busy Day!" There were poems like "Fuzzy Wuzzy" and "Ladybug, Ladybug."
And then there was this one:
Step on a crack,
Break your mother's back.
Now, my mother has SEVERE scoliosis, so much so that her back looks like the number seven from the side. So when I was little, I thought that one day, when I wasn't paying attention, I had stepped on a crack and that is why my mother's back was broken.
Now, even when I was little, I knew that if someone's back was broken, they could die from it. So I took my mom's condition as a warning that if I stepped on another crack, she would die.
So it's sixteen years later, and I still won't step on sidewalk cracks if I can help it. I am more careful about it when I am walking by myself.
But if you ever walk alond the street with me, and see me sort of hopping around weirdly, that's why.