The rain is all my fault

This afternoon I was visiting a sweet little old lady to whom I give a manicure each week. I commented that as I was walking across the driveway, I stepped on a spider.
"Oh," she replied, "That means it's going to rain soon!"
I figured it was just one of those "Old Wives' Tales," but freakily enough, as I was walking back out to my car, a few raindrops started hitting the pavement. By the time I made it back into town, it was definitely raining.
Huh! Who knew?
(Feel free to pass this bit of meteorological advice on to your local weatherman.)