It is interesting enough that one is likely not coming to a worker reunion if one had bad experiences. So it is even more likely that we tend to recall more pleasant experience. We human seem to have a need to revisit the past that we spend a great deal of time, like schooling, WWII, etc. What is it that we look for in these reunion? Relive a moment of our past or a great excuse to spend time together? It does not matter what the reason is - it is good that we do it. I believe it help us moving forward in our lives.