I am acutely aware that I need to ask a question, but I can't figure out what it is
The philosophy of the thing on the tip of your tongue
I take this piece’s title to be a nice first pass at describing a common feeling. Banana Yoshimoto, in The Premonition, provides us with a useful second pass:
I couldn’t have been more fortunate, and yet, from time to time, I couldn’t help but think—
It’s not just my childhood memories. There’s something more important I’m forgetting.
(p. 18)
The main character, Yayoi, went about her life as normal. But every now and then:
In my mind, a light would go off. Something’s missing. There’s something else.
(p. 18)
Eventually, she sets off on a journey to recover what has been lost. But before she leaves, she once more has an odd sense:
But something felt different…I kept second-guessing myself. I started packing my travel duffel, and stopped again. There’s no coming back to what I have now, not this time. Leaving now means setting something big into motion.
Somehow, I was sure of it.
(p. 37)
Now, you’ll have to indulge me with one more example. This one is from Proust’s Swann’s Way.
I raised to my lips a spoonful of the tea in which I had soaked a morsel of the cake. No sooner had the warm liquid mixed with the crumbs touched my palate than a shiver ran through me and I stopped, intent upon the extraordinary thing that was happening to me. An exquisite pleasure had invaded my senses, something isolated, detached, with no suggestion of its origin. And at once the vicissitudes of life had become indifferent to me, its disasters innocuous, its brevity illusory - this nev sensation having had the effect, which love has, of filing me with a precious essence; or rather this essence was nor in me, it was me. I had ceased now to feel mediocre, con-tingent, mortal. Whence could it have come to me, all-powerful joy? I sensed that it was connected with the taste of the tea and the cake, but that it infinitely transcended those savours, could not, indeed, be of the same nature. Where did it come from? What did it mean? How could I seize and apprehend it?
I drink a second mouthful, in which I find nothing more than in the first, then a third, which gives me rather less than the second. It is time to stop; the potion is losing its virtue. It is plain that the truth I am seeking lies not in the cup but in myself. The drink has called it into being, but does not know it, and can only repeat indefinitely, with a progressive diminution of strength, the same message which I cannot interpret, though I hope at least to be able to call it forth again and to find it there presently, intact and at my disposal, for my final enlightenment. I put down the cup and examine my own mind.It alone can discover the truth. But how? What an abyss of uncertainty, whenever the mind feels overtaken by itself; when it, the seeker, is at the same time the dark region through which it must go seeking and where all its equipment will avail it nothing. Seek? More than that: create. It is face to face with something which does not yet exist, which it alone can make actual, which it alone can bring into the light of day.And I begin again to ask myself what it could have been, this unremembered state which brought with it no logical proof, but the indisputable evidence, of its felicity, its reality, and in whose presence other states of consciousness melted and vanished. I want to try to make it reappear…
(p. 60-61)

These two passages have something in common. In the first, Yayoi has forgotten something. But she has not forgotten that she has forgotten. That is still quite clear to her. She is also aware that she has forgotten not just anything — she did not simply forget who "won the game" — it is something important.
Marcel, the character in Proust’s Search, is much the same. He takes a bite of the madeleine and is overcome. But by what? There is something inside him, a truth that the taste of the madeleine brings to the surface. But it does not really bring the truth to the surface. It simply brings the truth that something resides within him, waiting to be found, to the surface. He, like Yayoi, is aware that he knows something — or remembers something — important. But he does not know what it is, and try as he might, it will not reveal itself to him.
Now, there is an obvious sort of paradox here. How could these characters know something is missing and not, at the same time, have a sense of what it is? If we see a pothole in the road and say, “Ah, there is something missing,” this is only because we know that there is something—asphalt—that should be there, but for some reason is not. But, and here is the paradox, if we did not know the thing that was supposed to be there—that roads are ideally flat and without dents—we would not have much of a sense that something was missing.
I am intrigued by this. Does this mean that our characters—Yayoi and Marcel—do know what is missing? If so, why are they surprised? Why are they curious? Why is it a question or a problem to be solved for them?
Of course — you might retort that all this rests on a confusion. That: to know that something is missing, we need to know what the missing thing is. This may be appealing at first, but is certainly (at least not generally!) true. Consider: a student is sitting in a math class, learning about long division. The teacher is explaining the steps, but seems to skip one. The student is not sure how to arrive at the supposed answer. “I think you must’ve skipped a step,” she says. She is confused. The teacher would not be a good one if they responded: “Well, you’ve noticed the missing step, so you must, therefore, know what it is.” No, her problem is that she does not know how the answer has been arrived at. Our student knows something is required to move from step a to step c, but that does not mean she must understand step b, only that there is a step b.
So, there is a sense in which what at first appeared paradoxical is perfectly normal.
What are we, then, to make of Yayoi and Marcel’s cases? Are they completely normal—like a student asking a question in a math class? I think not. There is certainly something special about their cases. But what is it?