Lights that work, lights that don't work

Why is it that every year when you pull all the christmas lights out some work some don't. Half a string is good, half a string is not. Every year is the same thing, boxes full of decorations and lights that I end up throwing away after losing my patience, kicking them, calling them "names" and then just sitting there in the middle of the garage laughing at myself for acting like a little kid. But you know what, it is frustrating. I ended up throwing away 6 strings of gutter lights all my bushes lights and a couple more strings that didn't work. It used to be my house was the Grisswold house of the culdesac since not to many people puts up lights around here...grinches. You know what, I'm buying more and putiing them up, I like looking at them even if I have to do it all over next year.