I called a friend on my cell phone and another, completely unrelated friend answered. It turned out that the last 7 digits of both phone numbers were equal
It's not all that unusual, but it might indicate that you have too many friends and call them too often. Anyone in your "clique" will see the same "collision". I came out of a meeting at night, started driving home, and was annoyed that the lights on the radio panel were burned out. No, that wasn't it, there were too many lights. Or something. A few blocks later I began to wonder why in the world my husband had put a folded towel on the passenger seat. Whatever was on his mind? Unless ... this wasn't my car. No, it wasn't. I started driving back to where I had parked, worried that the car's owner had by now discovered the loss and called the police. Or, should I think seriously about whether or not this was a better car? It was certainly cleaner than mine. I found my car where I had left it, parked in the space next to it, locked the borrowed car, and drove away. How unusual is that? Well, the car is a very common model, so the probability of parking next to one it pretty high. The keys aren't drawn from a terribly large space, and older cars become more accepting of alternate keys. Now I am more careful about checking for my bumper stickers before getting in the car. I think "Ultimate Frisbee" and "Soaring" provide enought bits of entropy for all practical purposes.