The technical definition and how the term is popularly used are two different things.
As popularly used, we could say a megalomaniac is someone who truly believes that they are more important than everybody else. Often super bad guys in films are given the label megalomaniac, because they think they should be allowed to rule the world, or they are trying to do so.
The technical ("correct") definition of the term is that the person has delusions about the importance of their own wealth, power, etc. If a person truly has wealth, power, they aren't a megalomaniac, but something else (good or bad).
I suppose the thing about what it takes for a person to be called a megalomaniac, is that whatever self-importance they ascribe to themselves, it has to be well out of proportion from what most other people feel they deserve.
As popularly used, we could say a megalomaniac is someone who truly believes that they are more important than everybody else. Often super bad guys in films are given the label megalomaniac, because they think they should be allowed to rule the world, or they are trying to do so.
The technical ("correct") definition of the term is that the person has delusions about the importance of their own wealth, power, etc. If a person truly has wealth, power, they aren't a megalomaniac, but something else (good or bad).
I suppose the thing about what it takes for a person to be called a megalomaniac, is that whatever self-importance they ascribe to themselves, it has to be well out of proportion from what most other people feel they deserve.