A friend told me a few days ago that Snape was much better than James and that Lily should have stayed with him. I had no choice but to give a TED Talk explaining why that was light years away from being true. This part of the last book is a good example of this. Remember, this is supposedly the book that improves Snape's image and shows who he really was. However, we see how he proceeds to erase Lily's history. The letter she wrote to one of her best friends expressing her affection and the photo where she's happy with her family—he tore them up to keep a part of her that never belonged to her. He didn't see her as she was, but as he wanted to see her; he saw her as an object that belonged to him. That's why we should doubt his version of the story, because it's under his influence. Furthermore, his behavior at school with the Marauders is no excuse, because even if the bullying were true (which I doubt; I always saw it as a fight between gangs against the future Death Eaters), that doesn't give him any right over Lily or her decisions. James changed and became the person she loved and wanted in her life. Snape saying he loves her doesn't give him the right to demand she love him back, nor to erase parts of her history to suit his needs (as he did with the letter and the photo). Snape cut James out of that photo, just as he didn't think of himself or his son when he begged for Lily's life, demonstrating how inconsiderate he was by not considering how the deaths of her husband and son might affect her. He never cared about her; he didn't love her, he was only obsessed with the idea of her. That's what Dumbledore used to his advantage, like another pawn in his war. He was also a terrible teacher, mistreating all the children, especially Neville (Snape was just as responsible for his parents' situación as he was for Harry's, and he knew it but never cared), which shows what kind of person he really was, and it's as if Neville, even if he had been the Chosen One, wouldn't have switched sides. He also mistreated Hermione despite her suffering as a Muggle-born like Lily, he held a grudge against a boy for resembling his father, and he got Lupin fired from his only stable job. He always held grudges, he never matured. He didn't die for Harry; he never saw him except as a shadow of James and Lily, but he never truly saw Lily either. She was just an example of his obsession, an idea that she was the only one he could ever love. In contrast, James gave his life for his family, fought in a war he didn't need to participate in on the side that had everything to lose, didn't hesitate to risk his life to learn about Snape, and when he loved people he did it with all his soul as could be seen by how he treated others.
