They really aren't. Memories are a figment of our imagination brought to life, captured in elements such as photographs or the sounds we encounter as we perform our mundane chores. They are so real (perhaps almost so, but really not safe to say so) that we are cajoled into believing so. Because of that, these memories are but the things that capture how we feel and interact with a particular thing or person(s). It is the very determinant of the way we behave and attempt to understand the people whom we think we know but quite frankly, memories are a reminder of what has been and never what is to come. We all know the cliched that change is the new constant but we are so fixated with such an idea that we have reduced change to a predictable and rigid concept, insofar that we have lost its main and most fundamental essence--change is made and never merely recorded.
Memories are forged so we can look back and remember how it was back then but it is not a symbol of culmination, as it is often taken as such. It is merely a marker, a checkpoint in the whole length of the journey that we are not even halfway through. What is the point if we make memories but choose to hold them as such; precious and golden because they are crafted intricately the way we wanted them to be. That momentous picture after having taken it 5 times over just to capture the perfect lighting and the timely flash. But all that for naught. We look back very so rarely and in due time we will only hold on to these memories (and perhaps the back stories) but there is nothing more.
I am not saying to discard these memories for all is lost; rather, I am asserting that the emphasis on memories has taken a toll on what we choose to do with these memories. As passive individuals, we are inherently inclined to just bury these memories and reminisce the times once in a while, shed a tear if you are melodramatic enough, but after that we sit that admiring and basking in the same memories repeatedly. But we never seem to question ourselves: what next? After all, there had to be a first memory before your second and the second would have been the precursor to the third and so on (as long as your list of memories go on). When we choose to end that final memory with a photograph, we have decidedly severed ties and cut off whatever possibilities we could have embarked on if the friendship prevailed and the memory, not just simply preserved, but relived. It is such that I wonder whether memories are simply there to relieve our guilt in forsaking some of our relationships because it is certainly not wise to devote all of our attention to every individual equally; some are no doubt more important but this does not render the rest any less precious or worth treasuring. Perhaps, it is in such instances that memories play an important role in fossilizing the past through print and imagination; passive but nonetheless occasionally (mentally) active.
The bigger point here is that the more you cherish a particular memory, you more you should never let it end as a memory. Continue to hold on to that relationships and build on that and make more memories. Memories aren't simply built to last; they are built as a foundation for even more solid and grounded occurrences that will stay rooted and entrenched in our heart and soul. Memories pave the wave for us but it is our decision to either encapsulate these into a simple photograph stashed away into a secret compartment we revisit from time to time, or loosely throw that memory together with the rest in the growing pile because there is little need to hold on so tightly to what has past and you are still alive and kicking and ready to make new memories. The past can always be easily relived with the people itself rather than staring blankly and aimlessly at a digital screen, hoping someone could feel your emotions through your tweets.
Point is, don't whine or complain about how memories remind us of the past. They only hurt and drive melancholy when the memories serve as a final marker of our journey; instead, they should be used as a driver and stimulus for furthering more memories, and for paving the future. So cherish the memories, but don't let it end there.