Isn’t it ironic that the last quarter of life is a time we live in memory and also a time when we lose memory?

If we are rooms that have been filling up with life for three or four score years, then isn’t it amazing that we have this incredible library to draw on? Not just the turning points: bonding our lives to other human beings, seeing new life we have made, winning games and prizes and acclaim, losing people we love. But we can literally get down in the weeds of our experience: the day I sat with my sister on Ransom Hill, my back to a granite boulder, searching for tiny wild strawberries in the grass. The day at the lake when I had a chance to kiss Lynn Theller as she leaned against a tree and didn’t do it. Watching my son tie his shoes by himself for the first time; realizing this was the reward of being a parent.

But even those are bullet point events. And yet there are so many that are on the shelf: the fried chicken I bought from Winco a few days ago; or putting cardboard on the garden so I can cover it with mulch; seeing an opossum on the front rail. Some of these memories will hang around for a while; others will evaporate in a few minutes. What did I have for dinner tonight? Clam chowder and toast. What was yesterday’s dinner? Fish filets. But I have to strain to retrieve earlier meals…unless they have ‘flags’ of being tied to some significant event.

Effort to remember events I want to know. Poignant, uncomfortable recollections I would prefer to see fade.

And that’s where the gentle sisu has to kick in. Sisu is not only finding the strength to fight fierce enemies or overcome a physical limitation like running over ‘Heartbreak Hill’ in Boston. It is summoning the cool to wait until the name of your college roommate reappears in your ‘ken.’ Finding a way to look wise while delivering a talk and forgetting that very important concept you want to gift to your audience.

But sisu is also a weapon for fighting ghosts. How can my sister not snap at her husband when the way he touches her on the shoulder sparks a visceral memory of someone who took her by force? What do we do at an elegant party when a subtle smell of lamb chops reminds us of being a tiny child smothered by an overenthusiastic sheep?

Memories don’t line themselves up to be accessed at just the appropriate moment. They can say, ‘boo!’ like sidewalk clowns spooking crowds by popping out of innocuous trash cans. So often we aren’t free to fall to pieces: when we are with our children, or a work, or on a romantic date with a lover. Quick, where is that handy jar of sisu I didn’t know I would need?

And then there is the roof falling in; losing who we are and what and who we care about because age-based amnesia is stealing our very personalities. Or those of the ones we love most. How much of me do I lose if my spouse doesn’t remember the life we have lived? If my child’s name does not ring a bell. If “go get your coat and we can get some dinner” is met with “where do I keep my coat?”

Once, when I was taking a hard exam I realized that the effort of lifting my brain cells to the place where I kept the info was making me sweat as much as if I were lifting sandbags. In my last quarter that weight-lifting applies more and more to ordinary events of life: recalling a password, remembering to pay a bill, telling my brother the name of a favorite song. And it truly is sisu when the small lapse triggers a big fear. When imagination is strong; and evokes a time in the near future when the whole house falls down and none of the bookcases is left standing.

There is a sweet booby prize: I can let it go. I can say, “Damn it, I’m old, I can’t remember the stupid name.” I can ask my friendly A.I. device to retrieve the memory for me. I can ask kids and grandkids, friends and neighbors to be my historians. I can read. I can use it as an excuse to call someone I haven’t spoken to in a while. I can sit on the deck in the dappled shade and think of at close to nothing as possible.

But when that senior friend of yours is fetching for something you know, and they say, “No, wait, wait, it’s on the tip of my tongue.” Be patient. Know they are doing some heavy lifting, summoning the sisu required to be there, present, still in the game. Remember, if you are fortunate, you will arrive in that same crowded waiting room one day and you will need your handy bag of sisu and the sweet tolerance of others.

And please feel very free to add below your own stories of how and when you summon seniorsisu to get past those senior moments.