Marcel is unwittingly laying a foundation for becoming a certain sort of writer. This is one of the few passages outside of Time Regained that describes the laying and recalling of unforced memories.
On my way home I perceived, I suddenly recalled the impression, concealed from me until then, of which, without letting me distinguish or recognise it, the cold and almost sooty smell of the trellised pavilion had reminded me. It was that of my uncle Adolphe’s little sitting-room at Combray, which had indeed exhaled the same odour of humidity. But I could not understand, and I postponed until later the attempt to discover why the recollection of so trivial an impression had filled me with such happiness. Meanwhile it struck me that I did indeed deserve the contempt of M. de Norpois: I had preferred hitherto to all other writers one whom he styled a mere “flute-player,” and a positive rapture had been conveyed to me, not by some important idea, but by a musty smell. (II,91)