Summary. Batman will never retire, because fighting crime is the only way he can keep his parents' deaths from becoming meaningless, in his trauma-induced conception of things.
After the second Robin, Jason Todd was murdered, Bruce Wayne retired from being Batman and chose to live a regular life. Ten years later, a 55 year old Bruce Wayne tried to get his thrills in other ways such as Formula racing, driving a black car.
Immortality: Gained immortality from the Lazarus Pit by a fusion of his soul with Ra's al Ghul's; restored to the prime of life in 1979 at over sixty years old, by 2919, he had determined that he was physically only aging a year for every century.
One night, a heart attack forces Batman to betray a lifelong principle by threatening a criminal with a gun (the same one that murdered his parents), despite already wearing a new, high-tech Batsuit. Subsequently, Bruce Wayne decides to retire the Batman persona, and crime fighting in general, permanently.
If you remember this scene from “The Dark Knight”, Harvey Dent said that “Whoever the Batman is, he knows he cannot do this forever. Maybe, he is looking for someone who can take his place.” And this is the exact reason why Batman/Bruce Wayne disappeared at the end of “The Dark Knight Rises”.
Unlike his eternally youthful peers Wonder Woman and Superman, Bruce Wayne ages and has had to retire as Batman more than once. Unlike his eternally youthful peers Wonder Woman and Superman, Batman ages. That means he's been at fighting crime in Gotham City for over eighty years in the comics, TV, and movies.
Batman Forever was released on June 16, 1995, to mixed reviews from critics, who praised its performances (particularly Kilmer, Carrey, and Jones), visuals, action sequences, and soundtrack, but criticized its screenplay and tonal departure from previous films.
So assuming he hangs his boots up and assuming he's not irradiated, we would estimate that he'll live to at least age 90, which is our forecast for average life expectancy. However, he could also easily live to 95 based on the fact that he's smart, fit and wealthy and at some point likely to meet the 'right woman'.
He would simply keep being Batman until the day Batman is no longer needed. However, Bruce would probably retire somewhere in his 50s or maybe early 60s. At that point, even with his peak human fitness, he'll start slowing down considerably and being Batman will become too dangerous for the old man to handle.
Under supervision of an elderly Bruce Wayne, he fights crime in a harsh, futuristic Gotham. At least forty years after the "current" adventures of Batman and twenty years after Bruce Wayne (Kevin Conroy) retired from the role, his secret is discovered by troubled teen Terry McGinnis (Will Friedle).
Terry is the vigilante known as Batman in the future, having taken over the mantle after the aging Bruce Wayne retired. He eventually learns that he is a biological son of Wayne, created through covert genetic engineering by Project Cadmus. However, neither knew of their relationship at first.
Although Batman is often seen as an immovable force for justice, there have been times when Bruce Wayne has given up for one reason or another. Defeats and low points are just as natural a part of any hero's journey as the highs of victory.
Summary. Batman will never retire, because fighting crime is the only way he can keep his parents' deaths from becoming meaningless, in his trauma-induced conception of things.
Batman's biggest advantage, his fortune, has been taken away from him as Vandal Savage buys out Wayne Manor and takes ownership of the Batcave. Bruce Wayne is no longer a billionaire and has lost his access to bleeding-edge technology, his base, and remaining armory.
Grayson has donned the cape and cowl to replace Bruce Wayne as Batman. His most notable spell as Batman followed Bruce Wayne's supposed death in Final Crisis, and sees Grayson adopt Damian Wayne, Bruce's biological son and his adoptive younger brother, as his Robin.
Using that team, Marvel's multiversal Batman analog is supposed to be the hero known as Nighthawk, but in reality, this hero has almost nothing in common with Batman. Instead, he's a simple pastiche of the hero, designed to pad the Squadron's parody of the Justice League.
In Frank Miller's Batman: Year One series, for example, it's explicitly stated that Bruce Wayne returns to Gotham City aged 25 after spending 12 years overseas. Just like Batman: Year One takes place over the course of 12 months, it can be deduced that Bruce Wayne was approximately 26 years old when he became Batman.
The first and the youngest actor to play a DC comic character Batman was Lewis G Wilson. At 23, Wilson, donned the cape in 1943 film series titled 'Batman'.
In Batman Begins, he comments that he avoids killing to avoid become like the criminals he faces, believing that doing so will make him no better than his enemies. In The Dark Knight, Batman comments that he "only [has] one rule", likely referring to this.
In any case, it would seem that Bruce felt like he was becoming too much like the people he'd sought to protect the city from to begin with. "He just couldn't cope with it, and that's why he decided to shut off his other side, Batman," as Muschietti describes. "And he hasn't been able to forgive himself.
Michael Keaton was the first to suffer the most common reason why so many Batman actors quit: creative differences. After Adam West's overtly lighthearted portrayal, several decades passed before Batman returned to live-action, but the success of Richard Donner's Superman made a Bat-blockbuster inevitable.
