Harry Potter: The Worst Thing Every Order Of The Phoenix Member Did

By far, Severus is one of the single most complex characters within the pages of the novels. A childhood friend of Lily Potter, his feelings grew into full-blown, but unrequited, love. Snape never truly got over losing Lily to James Potter. The flame he carried for her lasted until her dying day.

11 years later, when Harry eventually arrives at Hogwarts, Snape is now a professor of potions and absolutely merciless to the young student. He is needlessly cruel to him, singles him out for not being knowledgeable, and takes any chance he can get to deduct points from Harry's house, Gryffindor.

With full knowledge of his deeds, many of Snape's actions can be waved away by acting as a double-agent in the employ of Dumbledore. Gaining the trust of Voldemort, even the murder of the Hogwarts Headmaster was all part of a grander plan. However, none of that excuses the cold, callous way he treated a young Harry, whose only crime was having a father that Snape hated.