Draco was accidentally killed by Harry's curse while escaping after the war. Harry refused to accept this. Hermione, with Harry's permission, extracted all Harry's memories of Draco.
Harry entered Hogwarts and became a Defense Against the Dark Arts professor. One day while catching students on a night out, he saw Draco's name on the Marauder's Map, but everyone told him that the Malfoy family's young master had died at birth.
Harry went to visit the Malfoy couple in Azkaban and Pansy, who opened a bookstore of his own. The Malfoy couple kept it secret, and although Pansy was sarcastic to Harry, she was unwilling to say anything. From then on, Harry began to have some dreams related to Draco. Harry vaguely felt that he should know him, and began to rely psychologically on this "non-existent person".
Intention: wu