Boy, what a terrible feeling. One second, this magic gravity-defying (what is gravity?) object is at your behest, pulled closer at the slightest tug of your string. The next, it's suddenly gone. You're never going to see that balloon again. Balloon heaven. Or worse, property of another child. A great lesson to teach your kids -- hold on to what you've got, because you never know when you're going to lose it (although honestly I'm impressed with how little crying there is).