What is the thesis statement in the short story "The Incomplete Angler"?

In their book Essential Essays, Brian Green and Sarah Norton discuss essay writing techniques using examples that include "The Incomplete Angler."
"The Incomplete Angler" appears in chapter 15, "Narration," where the authors state that "all good narrative papers follow a basic pattern." Norton and Green state that narrative papers should begin with an introduction that outlines the themes and characters and then continue to tell the story in chronological order. The final paragraph should then conclude the story and reiterate its overall point.
Norton and Green call the introductory paragraph in this pattern the "thesis." Their example of a thesis statement from "The Incomplete Angler" is as follows:

While visiting a kind and well-meaning friend in Sarnia, I revealed myself to be an avid, if not very good, sports fisherman. My friend confessed that he found fishing slightly less enthralling than watching algae grow in his swimming pool, but he had a pal who was a fishing fanatic. A phone call later, I was to be the special guest of "Ol' Jack" on an all-day fishing expedition to the Thames River the very next day. It has taken me four years to recover sufficiently from this adventure to tell you about it.

In the authors' view, this passage contains what is needed in a thesis statement of this kind. It clearly states the story's main characters, location, time frame, and subject: the main characters include the narrator, who is a keen but average fisherman, and Jack, who appears to be something of a professional; the location is the Thames River in Ontario, Canada; the time frame is four years prior to the narrator's present; and the subject of the story is a fishing expedition. Additionally, the narrator alludes to what the story will contain by implying it was extremely traumatizing in some way; "It has taken me four years to recover sufficiently from this adventure."