You are right, not many would be willing to bet that Facebook will be as relevant in 10 years as it is now but I believe this thought is just part of human nature. We are always anticipating change, something better than what we have now. Nobody is wrong to think that,not that I am saying that is what you were implying with your statement. Along with pattern matching, I think it also has alot to do with what others think. It surprises me on a day to day basis how many people base their opinions of such things on the opinions of others.