BY FRANK TERRANELLA

There are a group of over-50 actors on Broadway right now in a play called “Love Letters” by A.R. Gurney. It documents the almost-lifelong correspondence between a man and a woman who come to realize that they are soulmates. But like the couple in another play “Same Time Next Year,” they always seem to be out of sync.

The play is performed entirely by actors of a certain age like Brian Dennehy, Mia Farrow, Alan Alda, Carol Burnett, Martin Sheen, Candice Bergen and others. These stars alternate in pairs over the four-month run of the show.

The format of the show is quite simple. On a stark stage with only a table and two chairs, the actors read a lifetime’s worth of letters.Slowly the relationship of the couple becomes clear, and we watch it mature as the years fly by. It’s a premise that is best appreciated by people who have lived more than half a century. Like the actors who bring the correspondents to life, we over-50s know long-term relationships for the long and winding roads they are.

The idea of a best-friend-forever (BFF) is more idealistic than realistic for most of us. BFFs are precious because they are the exception to the rule. For most of us, relationships with childhood friends, elementary school friends, high school friends and even college friends are limited to reunions every few years, if we are lucky. Most BFF relationships do not survive into the right side of 50.

Distance is most often the cause of losing touch. But changed circumstances can also contribute. For example, becoming a parent is often so demanding of our time that we lose touch with our single friends. It’s tough to get together for a drink after work when you’re rushing home to pick up a child from daycare. And even if you can get away, conversation becomes a problem when your focus is on children, and not seeing the latest movies, plays or museum exhibits.

But in rare cases, you can be so in sync with someone that the relationship stays alive. Oh sure the relationship has its peaks and valleys, but with a little effort you stay in touch. It’s actually a lot easier to do that today, what with Facebook, e-mail and instant messaging, although actual contact is still necessary.

Lifelong friends are a precious commodity needing to be nurtured. These days many young people may feel that since they have hundreds of Facebook friends, many of these will be BFFs. But being “friended” on Facebook doesn’t mean you have a friend. A friendship requires that you put yourself out to have human contact on a regular basis.These days that can be as simple as a regular Skype call. If Siri is the only friend you talk to on a regular basis, it’s time to use the phone part of your smartphone, and have a real conversation with someone you used to know.

Recently, I reconnected with an old college friend of mine. We had been in touch sporadically over the years. He lives in Maine, and so distance is a factor. He also hates cities, and so getting him to come to New York is always challenging. Most recently, we were in touch through Facebook. But I had not seen him in 10 years. So I decided that this was a relationship worth nurturing, and if Skip wouldn’t come to New York, I would go to him.

Now truth be told, going to Maine is hardly a punishment. It’s a beautiful place. But it is a LONG car ride since Skip lives near Augusta, which is still a few hours ride after you reach the Maine border. But my wife, Pat, and I chose what we thought might be a good weekend for foliage viewing, and we decided to get in the car and go. It turned out to be a great weekend and Skip and I got a chance to re-connect in a way that you just can’t do electronically.

When I talk to my stepfather about what it’s like to be 91, he tells me that the hardest thing is that all your friends are gone. You see, the forever part of BFF is not really “forever,” but only “for as long as we both shall live.”

It’s tough to lose friends to the grim reaper. But losing friends due to laziness is criminal negligence. Like plants, your friendships need attention, or they wither and die.

As we travel down the road of life after 50, it’s especially important to maintain contact with our old friends. They’ve traveled the road with us and they can bring out the best in us. At the very least, they remind us of our young selves. They remind us of a time when the road ahead seemed long and full of promise. They remind us that life can still be like that, even after 50.