Most times in fiction characters have revelations, or changes of heart or how they feel about things, by an event happening. For example in Batman, it's the murder of Bruce Wayne's parents that's the even that gets him into crime fighting. Or in most stories with murder in, someone may put a murder plan into action, but before it's complete, some event will happen that will make the character change his heart, and call it off. But can a character have a change without a specific event happening and it will still make sense, without feeling like an unnatural or forced switch? Does there have to be an event, or can it be completely character driven with no plot events? What if a murderer came up with a plan, but then changed his mind, because he realized he couldn't do it, just because? Or what if Bruce Wayne wanted to fight crime because he hated the very idea of crime in general, and nothing bad was ever done to him to cause it? Is this natural for the reader to accept, or does their have to be necessary event to kick it off and you have to make room in the story for it?