There is a short story, with a longer name than just "Persistence of Vision" but it evokes the feeling of things that endure. I have to admit I am always amazed at the endurance of emotional resonances in my life.
For example, while Robin was born on July 6 and died on August 31, I still associate the 4th of July and Labor Day with her birth and death and emotionally they hit me on those days rather than the "real" ones.
The other thing about emotion is that it is one thing to read and hear that the emotion of loss will linger, to have recounted David O. McKay's wife's story about how as a grandmother she stll felt the death of her infant son, quite another to experience that loss and pain persist. They become more endurable, more acclimated, even more distant, in a way, but there is a persistence.
This fourth of July week end brings joy, and rest, and peace and pain. But above all else, hope persists as well.