Those who refuse to learn from the past are doomed to repeat it.... or some hogwash like that.
While everyday man and woman do not live in times of turmoil that are the makings of grand narratives like that of World Wars or epic hero ballads, it is our relationships that serve as our version of history.
While deceptively mundane, a person's history is an amusing read at what he or she was, has become and quite possibly, will be. In fact, looking back at all those long list of friends and significant others that have come and gone is an enlightening activity that should be done whenever the current situation permits.
Majority of people would prefer to keep such things hidden or forgotten. People preach the need for closure and sometimes the best way to achieve that is to retrace one's steps. Closure is nice and all but sometimes a lesson must be learned. A relationship that ended and thought you nothing is a waste of time and more than likely just as deep and meaningful as that last fling or one night stand.
Some may get it right the first time and not even have a chance to build a history. These people are either so ridiculously fortunate or are in for a severe and disappointing ending. Shit happens.
Still, having a history and being able to recount it with someone who's shared that history is an experience that bests describes progress. People change, perhaps retrospect will allow one to view the history in a new perspective, and coming into peace with that will assure that regret will be kept at bay.
Face it, the past is just as much as a part of life and viewing it as something irrelevant is folly and ignorance in its purest form. So pick up the phone, call someone from the past up, and maybe, just maybe, one will learn something that day.