This made me love Severus so much. You could really see throughout all of his memories that he had reason to hate James and them. That he couldn't help hating Harry. That he truly loved Lily. You can't say that Snape was a villain after seeing this. You just can't. And if you do, I highly recommend you reread the series. And rewatch the movies.
It's cool how all of these lessons are things that people, young and old, can benefit from. It's sad that a lot of people think that Harry Potter is just a bunch of silly magic and nonsense. In contrast it is full of life lessons and realistic problems.