Two weeks ago I flew to the Midwest to visit my son, daughter-in-law, and their three children. As the shul rabbi, my son goes over after every Shabbat to make Havdalah with Ruth. At 94, Ruth is very sharp, very proper, and very German. But she has no short-term memory.

On her table lies a magnetic Scrabble board. Ruth has been playing with her companion.

“Look,” says my son, “Omeyn, on a triple-word-score!”

“That’s ‘omen,’” says Ruth. True to her heritage, she remains very correct and precise.

“He can’t help it,” I offer. “He’s a Rabbi.”

We have a pleasant chat. Ruth keeps asking the same questions. When did I arrive? How is my mother? My son makes Havdalah, and we leave.

His children are young. The oldest, not quite 6, is cuddly and very bright. (He is my grandson, after all!) We read books. We play games. He is as sorry to see me go as I am to leave.

As different as they are, Ruth and my grandson have one thing in common: neither will remember my visit. Ruth has already forgotten it. She probably forgot it before I left her house. The little my grandson may remember will be mixed with fuzzy images of other times, other visits, other relatives.

I won’t remember much either. Even two weeks later, many vivid impressions I had at the time have already faded. These will also blend in with other hazy recollections, the ones not lost altogether.

Although my mind is not going (yet), I forget a lot. I rent a movie from Netflix, and halfway through it a scene seems somehow familiar. Haven’t I seen this already? I start a book, only to realize I read it before. Or I might have. Why not read it a second time anyway, since I remember so little of it? Or then again, why bother if I’ll just forget it again? Someone talks about tutoring a high school student, and suddenly a blurry image pops into my head of a student I once tutored myself. I see him sitting in my medical school dorm room. I haven’t thought of him in 45 years, and recall nothing about the student or of teaching him. How did we meet?  Was the experience worthwhile?  I don’t recall.

People keep diaries and don’t consult them. We take photos to store in albums, real or virtual, and rarely look at them. (Smartphones let us take so many snaps that we could spend the rest of our lives staring at every trivial moment we’ve recorded, leaving no time for anything but the occasional selfie of us looking at where we’ve been.) Institutions keep meticulous records and store them in massive archives that, unless a random historian or grad students someday takes an interest, no one ever opens.

Why do we think remembering is so important if we actually remember so little?

Somehow we seem to think of memory as the thread that holds us together and connects us to who we are.  Dementia, the fate we fear as we age, snaps that thread. People who visit elderly relatives invariably comment on whether or not the person they see “remembers me” or not, whether they are “still the same person,” or, sadly, have instead “lost their personality.” Those of us who still remember things are sure we maintain our ongoing self, even though we’ve forgotten the vast majority of what has ever happened to us.

Holidays jog memories. They make it easier for us to recall specific things that happened once upon a time (but which year was that?), particular people, what they were like, who’s not around anymore, what we were up to then. At Pesach time we are asked to remember what happened to us as a people, that we were slaves in Egypt and were freed. What does it mean to remember something that happened before you existed?

Jews have a long memory. We assume that our experiences as a people have made us what we are.  In a similar way, we feel that—somehow or other—things that happen to us as individuals become part of our character and shape our personality. Even if the specifics are long gone from our consciousness, we figure they’re in there somewhere, doing something useful for the continuity of our selves, just as reciting the Haggadah reinforces our continuity as a people.

Remembering the past turns out to be about the future. That my grandson will forget my visit troubles me not at all. I assume — I hope –that whatever memory traces my visit leaves will become a small but permanent part of him and influence who is and who he will become and what he will think of me, if and when he does. Ruth’s memory loss, by contrast, feels very sad. As life draws to an end, it gets harder to think that my visit, or anything else that happens to her, will become part of anything sustained. Even though the person she still is remains clear—“Omen, not omeyn!”– watching her memory slip makes it impossible to ignore that, for her, time’s arrow points only down.

As persons, and as a people, we take the trouble to remember the past because we expect to have a future.