How did batman turn into batman?
According to the fictional story of Batman, a very rich businessman, named Bruce Wayne, once witnessed the murder of both his parents when he was a child, at the hands of criminals in the city of Gotham. When he grew up, he decided Gotham needed a hero, and he trained for years to become the Batman.
There are a few origin stories for Batman, especially when the first Batman has made way for successors. The most common origin story is that Batman's parents were killed by a criminal or villain during his youth, so he grew up fueled by a desire for justice and vengeance.