When you call up a memory, you destroy it. This is biology, not philosophy. Recall destabilizes the protein structure of storage, and your brain then constructs it anew: now you only remember the remembrance (Nader et al 2002). Plato would have a fit.
Philomena wonders how many times she’s thought about learning that. Since then certain things are off-limits, things she can’t even list for fear they’ll trigger the breakdown. They must be saved. She hoards them, breaths of her youth like untouched vinyl, kept cool and dry against the day she plays them back for the first perfect time.