One theme of this passage is: don’t brag about your accomplishments before you’ve completed them. how does the author use the details of the passage to develop that theme? the uncle tells the narrator a story about what happened to a man who bragged about something before he finished it. the narrator celebrates catching a fish too early, and he loses the fish in the process. the narrator’s uncle boasts about all of the fish he is going to catch on the trip but fails to catch any fish at all. the narrator brags about what a good fisherman he is, so his uncle takes him fishing to prove it.