It seems strange to me how differently two people can percieve and remeber the same experience. Psychology constantly begs the question, what matters more - our genetics our our environment? Just like all of these factors must be considered in psychology, I'm sure there is a myriad of things that affects our memories.
But lately, I've been thinking that our vices have just as much to do with it as our social or genetic factors. I've come to decide that everyone is insecure (not too big of a surprise there..) but also that everyone is vain. Don't we spend more time thinking about ourselfs and what others think about us than anything else? Why else would we think about what we wear, what we say, do. Why else would we strive to do well, or hate ourselves? Because at the heart of it all is self importance.
So, sometimes I wonder if people (consciously or not) actually remember the past as worse than it was because they need to believe that the present is better, that they have beat what held them back in the past.. And, hey, maybe it is and maybe they have. But the fact that we all need to find growth, improvement - instead of a plateau or stagnation, is incredibly self preserving. And self preservation is tied to our genes.
On the other side, isn't it possible to remember things better? To forget about the bad and romanticize the past? What's the first step that most people take when they encounter a problem? Pretend that it doesn't exist. Maybe it's to protect their sense of self, maybe it's because they don't want to believe that they could be anything less than happy, or maybe saying "that was me once. Wasn't I great?" is our own way of dealing with the problems of the present.
Either way, our memories can't be trusted.