If habit does weaken everything, familiarity also keeps us from being overwhelmed by the novel.
It is our noticing them that puts things in a room, our growing used to them that takes them away again and clears a space for us. Space there was none for me in my bedroom (mine in name only) at Balbec; it was full of things which did not know me, which flung back at me the distrustful glance I cast at them, and, without taking any heed of my existence, showed that I was interrupting the humdrum course of theirs. The clock–whereas at home I heard mine tick only a few seconds in a week, when I was coming out of some profound meditation–continued without a moment’s interruption to utter, in an unknown tongue, a series of observations which must have been most uncomplimentary to myself, for the violet curtains listened to them without replying, but in an attitude such as people adopt who shrug their shoulders to indicated that the sight of a third person irritates them. (II,333)
Then my grandmother came in, and to the expansion of my constricted heart there opened at once an infinity of space. (II,334)
Although habit will make the new room comfortable, eventually, the source of Marcel’s discomfort is more elementary. If his presence means nothing to the new setting, then this is a foretaste of mortality, of a world that can exist without him.
Perhaps this fear that I had–and that is shared by so many others–of sleeping in a strange room, perhaps this fear is only the most humble, obscure, organic, almost unconscious form of that great and desperate resistance put up by the things that constitute the better part of our present life against our mentally acknowledging the possibility of a future in which they are to have no part; a resistance which was at the root of the horror that I had so often been made to feel by the thought that my parents would die some day…a resistance which was also at the root of the difficulty that I found in imagining my own death…(II,338)