This is not the first such scene I have seen in Kenya.
The young woman in front of me, in the checkout line at the supermarket, lifts the products from the cart and stacks them one by one along the scroll roller that, as luck would have it, is not working today.
He does so carefully, almost blessing each purchase. Two packages of flour, an orange juice concentrate, tomato ketchup, seed oil, cookies, plum cakes, instant cocoa, toilet paper, tampons, chocolates, dishwashing liquid, a few other necessities and a few treats.
The woman pulls out her cell phone and with the calculator starts counting how much her groceries may be worth.
She knows full well how much she has left on her Mpesa. Luckily there is that, which of bank cards not a chance and cash, better to carry around as little as possible.
Her turn comes and some of the budgeted prices are higher than her calculations, that's when the cashier approaches the threshold of her funds on her cell phone.
"Tafadhali..."
Please. The woman asks the cashier to stop.
Her desires, coupled with the needs, exceed the budget.
It happens more and more often in this country where the youthful habit of consumerism is now coupled with the sudden halt in growth that has caused prices to spike and the shilling to sink.
Now it's a matter of choice.
Clearly, they skip the gluttonies, the non-essentials.
But you can't just erase a dream dreamed for half an hour between the aisles, a recurring dream that paralleled and crossed a few times through childhood and adolescence and still makes her feel like a Kenyan Alice in Wonderland.
We make one pack of flour and save the plum cakes...away with the tomato ketchup and in with the chocolates.
She picks up the instant cocoa, looks at the cashier.
Embarrassment perhaps not outweighing disappointment, she apologizes to me who evidently seemed too interested. I am always interested, by nature. Not just to tell about it, but because humanly I wish I could afford to tell the woman, "How much longer? I'll take care of it, hakuna matata. You were drawn today, congratulations!"
Without this prosopopoeia, I once did. He was an elderly gentleman, with a cane, bright eyes and a hint of a white goatee. He had definitely miscalculated, or maybe he had done his last shopping ten years earlier. He would save at most one-fifth of a whole range of items he wanted to take to relatives in the village. I had a good relationship with the cashier at the Arab emporium. "I'll take care of the rest," I told him.
He thought I knew him, and I implied that I did.
The old man thanked me obsequiously and ran away faster than his cane with his heavy bag, who knows for fear that I might change my mind.
I have known for a long time that I could never be rich, and if I have not become rich it is precisely because I would not be able to pretend in certain situations. When I see the dream prevailing over reality, the pure, instinctive afflatus that can't come true, I can't take it.
Although I have repeatedly pointed out that in Africa, "candy solidarity" serves little purpose because it is uneducational...in the face of a "mzee" who has already taken the clayey track of sunset or Alice in the land of big business...what do you want to educate? 
In a world overwhelmed by the pursuit of icy perfection, of inhuman but productive artificial intelligences, seeing a woman at the checkout counter of a supermarket simply hoping to go home with some instant cocoa, foretasting a glass of warm, sweet milk with her partner, friend or children, sets aside all rational reflection, even noble, and makes me think that, as the poet sang, somewhere there is still "a time dreamed of that one must dream."