You invite your friends over to watch an NBA basketball playoff game on TV. There are plenty of sodas in the refrigerator,the popcorn is popping, and you are all set to watch the big game. You turn on the TV set, and all you get are fuzzy images on the screen. Is this plain bad luck or is it Murphy's Law at work? Murphy's Law states: If anything can go wrong, it will.
Similar situations occur all the time. When you're in a hurry to open the door and you try several keys on the key ring, the last remaining key is usually the one that works.