In lines 20-36, fitzgerald writes about dexter's fantasies involving "imaginary audiences and armies" and golf tournaments. what do such fantasies reveal about dexter's character? why does the author choose to tell us about dexter's fantasy life?

-- What do such fantasies reveal about Dexter's character? That Dexter is a superficial and naive dreamer that fails to look beyond appearances. Not only are things not as epic and glorious to ego as he thinks but also that he fails to appreciate what he actually has, in favor of an illusion of something that does not even exist (his impressions of the external appearance and glitter of wealth do not even reflect on the underlying consequences of such wealth and on how these men actually got wealthy). He is thus incapable of understanding reality and his dreams are a distorted version of it based on his own projections.

-- Why does the author choose to tell us about Dexter's fantasy life? Because it provides the reader with an insight on the shallowness and futility of Dexter's quest. By comparing reality to dreams, Fitzgerald provides an inkling that foreshadows the end result of Dexter's quest: a dual occurrence of a bleak yet wealthy reality and his disillusioned, extravagant dreams.