Does one's memories define one's identity?

The idea that souls are a finite resource, and are somehow "recycled" is not a new one. And there have actually been true events that seem to support this idea. Some people seem to be born with souls that have not been completely cleared, and seem to know things about past lives that are unexplainable. The hope that Joe would remember anything is what is so poignant in this story. He tells her to look at his eyes and she will see it is the same soul in a different person "maybe even a quarterback". The movies "Eternal Sunshine of the Spotless Mind", "Memento" and "Solaris" all touch on this concept, and illustrates that incomplete memories of a "past life" can make you insane. This is why the memories in Joe's soul have to be erased - it is too much for a sane man to bear such knowledge.

"The great Johnny Rocco, with Nora's spittle hanging from his face."