Most women have them. Most men don't understand them. It's the bag of bags.
A few years ago a friend and her husband moved from their apartment into a new home. They were packing and she was putting the bag of bags in a cardboard box. Her husband asked her incredulously, "are you seriously bringing that bag of bags with us to our new place?" She said, "of course! Do you know how many years it took me to collect these bags?" In the end, she won the argument and the bag of bags went with them.
I don't understand why men can't understand this.