In Joan Didion's "Blue Nights," the author reflects on the nature of memories and mementos. She suggests that while these objects are intended to evoke vivid recollections of past experiences, they often highlight how little we valued those moments when they occurred. This realization reveals a deeper sense of loss, as it exposes the gap between our current understanding and our past appreciation.

Didion emphasizes the painful contrast between memories and lived experiences, implying that our inability to fully appreciate significant moments at the time adds to the sorrow of their passing. The sentiment underscores a universal struggle: recognizing the fleeting nature of life and the regret that often accompanies hindsight.