I owned a black cat once. Never bothered me, crossed my path dozens of times a day and didn't bring me any bad luck.

No, wait. Shortly after we got the cat my wife got pregnant. Then she got pregnant again. After we got rid of the cat she stopped getting pregnant! They DO bring bad luck!

And no, I don't have any superstitions. How can you believe any of that when half of the things that are unlucky here are lucky somewhere else?