Throughout our lives, we make hundreds of friends: neighbors, classmates, teammates, colleagues, trainees and those individuals who we meet serendipitously at social events. Unfortunately, over the years, we lose touch with most of them.
Except for those who use the "shotgun approach" via social media (which results in ongoing superficial relationships) most of us end up staying in touch with only a handful of close, long-term friends. Even these individuals may only be contacted a few times each year, primarily on birthdays and holidays.
Of course, our modern, mobile society is at least partly responsible for this phenomenon as home town relationships fall victim to economic opportunities elsewhere. But I suspect it reflects the evolution of human culture in general, especially the loss of interdependence among family and community members. Nevertheless, I believe it is important to regularly connect with old friends; after all, we have, at least in part, been shaped by those relationships.
See also: Old Friends