A piece becomes memorable when it creates a feeling harder to summarize than the object itself.
CREATIVITY
WHAT THIS MEANS
The works that stay are the ones that leave you with a state you cannot compress into a sentence. You can describe the plot or the image easily; what it did to you resists paraphrase entirely. That resistance is the sign that something got through rather than merely being understood.
Notice which things you cannot summarize when asked. Those are the ones worth returning to. The ones that reduce neatly to their point have generally already given you everything they have.
A QUESTION TO SIT WITH
Which work of art have you never been able to describe well?
Free, with nothing to buy inside it.