WARNING: The following article contains spoilers for Legends of the Dark Knight #16 by Yedoye Travis, Nina Vakueva, Ivan Plascencia, and Ariana Maher, on sale now.
Batman is a hero who is without a doubt defined by his past. Bruce Wayne was forever changed after his parents were shot in Crime Alley after their viewing of The Mark of Zorro. This would prove to be Bruce's greatest motivation for becoming a vigilante, with him continuously drawing on the memory throughout the years. Unfortunately, the machinations of the Scarecrow have taken away the Dark Knight's ability to draw on this source of power and inspiration, while also providing a possible explanation as to why DC continues to revisit the tragedy, especially stories told from Batman's point of view.
In Legends of the Dark Knight #16, Scarecrow injected Batman with a toxin that elicited an extremely lucid nightmare of the night his parents were killed. However, in the confines of the dream world, the Caped Crusader was able to save the day, stopping the event from ever happening in his mind. He is only shaken from the vivid dream by the shouts of the younger Bruce Wayne.
When Batman awakened, Scarecrow explained that he had been studying the vigilante for years, trying to understand his motives. Scarecrow added that he had since developed a new drug that would allow a person to remove their darkest memory, which he had now used on the Dark Knight.
Bruce returned to the Batcave where he spoke to Alfred about what happened. The two worked together and developed a procedure intended to return the tragic memory to Batman's mind. Alfred tried to reason with Bruce, positing that perhaps what the Scarecrow had done was for the best, but Bruce was adamant in his decision. He was put under anesthesia and returned to the night of his parents' deaths. He was able to admit to himself that he did feel better without the memory, but he also realized that without it, there would be no reason for him to continue being Batman.
This creates an interesting glimpse into the Batman mythos and how he truly feels about his parents' deaths. As horrible as this memory is, it is the only thing truly keeping Batman going. Without this memory, or at the very least access to knowledge about the events, Bruce feels that there is no way for his alter ego to exist.
In a meta-textual sense, this could provide an explanation for DC's continuous revisiting of the events surrounding Thomas and Martha Wayne's deaths. Almost every Batman movie opens with the notorious scene in Crime Alley. Many of Batman's comics have also delved into this event and continually revisit it as the series continues.
Legends of the Dark Knight #16 provides a reason why this scene is shown so frequently: It is absolutely essential for the continued existence of the Caped Crusader. Although he admits that he feels better without the memory, Bruce Wayne knows that his pain is necessary as it guarantees the existence of one of DC's most iconic heroes. Since so many Batman stories are told, at least to some extent, from his point of view, this gives the repeated scenes of their deaths, as well as the slight alterations to the scene, an in-universe reason to be presented at the forefront of Batman's mind.
For readers and viewers, the repeated exposure of the Wayne Family murders underscores their foundational importance to the Batman mythology/ But for Batman, these repeated moments may very well be the only thing keeping his final memory of his parents alive.