Just why??

All of a sudden, I found myself thinking of sociologically when I was watching my friends play Pokemon at school. I then was thinking oh yeah we all used to play that in the 90's but then it just died off. Why? Why do we love fads? We like something at first then we just get sick of it or even bored of it. At first we think well maybe we could make this into a fashion but at the end of it all it was just a bad idea. In 2010 the new thing was Silly band. The most pointless thing in the world but people wanted more and more of it. I want to know why we do this. I still don't get it. http://www.crazyfads.com/