In recent years my mother, a son, a brother, and several close friends have passed out of my life. As reminders of my own mortality, some of those losses have left me wistful and pensive; others have been so oppressive that I did not know how the people I saw on the street could continue to exist without taking note of how the world had changed.

The same emotions often overtake a survivor when the other person in a couple is no longer in the picture. There is something about married life that makes living alone intolerable for many people after the death of a spouse. This appears to be especially true for men.

A case in point was in the news recently, after a 94-year-old man died in a small town near Albany on the way to the funeral of his wife. Through their 66 years together, each had promised not to leave the other behind. The local funeral director, who also happened to be the coroner, rose to the occasion and held a joint funeral.

I once had a friend, a renowned and respected academic, who lost his zest for life after his wife died. All his renown in the profession meant nothing to him. He dispiritedly spent his last three years looking forward to spending eternity with Ruth.

When my brother died last year, on my desk was an article about hockey I was going to send him. I knew of nobody else who would have wanted to read it, nobody else to share it with. Jerry and I had grown up developing a similar appreciation for hockey, and now the game itself seemed empty.

Much of its meaning for me, it seemed, had been in what we could share. With my brother gone, I knew nobody else who could understand references to games and events of the 1950s unless I spelled them out, and certainly nobody who would care. Not his children, not my wife, not my children, not his wife.

There are many things that family members can know without having to explain them to each other. The same is true for close friends, who can get together for the first time in years and pick up conversations as if they had been interrupted the day before.

The two parties in any personal relationship share psychic energy, they share memory, they share an outlook. Those elements almost make the relationship itself seem like a third party. It is always present, and they are always aware of it.

In one of his stories, Carlos Fuentes observed that we lose the past when we die, not the future. And the people who have shared life with us also lose some large dimension of that past.

If you were with somebody on the day you were drunk at Xochimilco, or lost on Mykonos, that other person gained a memory of you next to her just as you created a memory of her next to you. The loss of your life or hers breaks that connection. This is also one reason why divorce can seem as painful as death.

It is common for spouses to argue about what happened in the past. Couples become custodians of each other’s memory. When one starts to tell a story, the other steps in to correct the details. They act as more of a memory check than a reality check for each other, but what they remember of the past does not necessarily reflect what actually happened; it only demonstrates the individuality and uniqueness of individual memory.

Friends and family members grieve when death separates them, or when dementia silences the laughter that used to be a common bond. Their mourning for the end of a relationship has as much to do with the memories that can no longer be shared as with the person who played a part in them.