1. Defense Against the Dark Arts:
* Practical skills: Snape was a skilled and knowledgeable DADA teacher, despite his reputation. He instilled in Harry the importance of defensive spells and strategic thinking in combat. He specifically trained Harry to fight off Dementors, a skill crucial for his later survival.
* Understanding the Dark Arts: While Snape himself was deeply involved in the Dark Arts, he believed it was essential for wizards to understand them to combat them. He exposed Harry to dark magic, not to corrupt him, but to prepare him for the threats he would face.
2. Occlumency:
* Mental defense: Snape taught Harry Occlumency, a powerful skill to protect one's mind from intrusion. He knew Harry's mind was prone to attack, especially from Voldemort, and aimed to equip him with a defense.
* Understanding Voldemort's mind: Snape, privy to Voldemort's thoughts through Legilimency, used the Occlumency lessons to teach Harry about Voldemort's mentality, motivations, and plans. This knowledge proved invaluable to Harry.
3. The Truth About His Parents:
* Lily's sacrifice: Snape's constant reminders of Lily's love for Harry and her sacrifice were not meant to be cruel, but to demonstrate the power of love and its impact on Harry's life. He wanted Harry to understand the depth of his mother's love, the source of his own power.
* The flaws of his own actions: Though Snape was burdened with his own past mistakes, he indirectly revealed them to Harry. He showed him that the choices he made were driven by love and loyalty, though misguided at times.
4. The Value of Courage:
* Standing up for what is right: Snape's life was filled with difficult choices, and he often had to do what he believed was right despite the consequences. By showing Harry his own struggles, Snape taught him the importance of courage and the need to stand up for what is right, even when it's hard.
5. The Importance of Trust:
* Learning to trust: While Snape was often difficult and secretive, he slowly earned Harry's trust through his actions. He became a confidante and advisor, sharing his knowledge and protecting Harry from harm.
* Forgiving others: Snape's life was marked by loss and betrayal, but he ultimately found a way to forgive and trust Harry, despite his earlier animosity. He learned to see Harry not just as James' son, but as a good man in his own right.
In summary, Snape's teaching of Harry wasn't just about DADA or Occlumency. He aimed to prepare Harry for the challenges ahead, protect him from Voldemort, and help him understand his own powers and legacy. Although his methods were unconventional, Snape's actions were ultimately driven by his love for Lily and his desire to ensure Harry's survival.