Pleasure like the Development of a Photo

From Within a Budding Grove, the Moncrieff-Kilmartin-Enright translation:

But so far as the pleasure was concerned, I was naturally not conscious of it until some time later, when, back at the hotel, and in my room alone, I had become myself again. Pleasure in this respect is like photography. What we take, in the presence of the beloved object, is merely a negative, which we develop later, when we are back at home, and have once again found at our disposal that inner darkroom the entrance to which is barred to us so long as we are with other people.