Oh wow, I had never thought about Snape's Hogwarts experience being such a stark contrast to Tom and Harry's! Snape is such a heartbreaking character. Second only to Dumbledore to me in terms of favorite characters. They have a lot in common, actually, both being haunted and driven by regret. Weird, I guess, that I never read fic featuring either of them, but they're kind of sacrosanct to me as JKR wrote them.