The first chapter is full of metaphors and images that are never mentioned again. One object Therese ponders is a pair of gloves a nun gave her:
Therese had kept the green gloves at the bottom of her tin locker at school. […] Finally, they were too small to wear. (1.12)
Thinking of the gloves is what eventually inspires Therese to take action and send Carol a card. She may be young, but Therese realizes things don't last forever—and the memory of something isn't that good if that object was never used, or in the case of Carol, the subject was never pursued.