The most relevant quotations are unsurprisingly in the sixth chapter, which was the original short story.
After a night at fight club, everything in the real world gets the volume turned down. Nothing can piss you off. Your word is law, and if other people break the law or question you, even that doesn't piss you off....Perhaps I just don't get it, but for me those quotations do not seem realistic.
I felt finally I could get my hands on everything in the world that didn’t work, my cleaning that came back with the collar buttons broken, the bank that says I’m hundred of dollars overdrawn. My job where my boss got on my computer and fiddled with my DOS execute commands....
Nothing was solved when the fight was over, but nothing mattered.
It certainly is true that becoming capable and confident in some kind of physical competition is a vital part of healthy masculinity, which cannot be replaced by being capable and confident in other areas. But I have never seen in my life or my friend's lives that being capable and confident in any kind of physical competition creates a sense of overall sufficiency the way the narrator describes.
I asked Tyler what he’d been fighting. Tyler said, his father.Maybe this is the clue. The narrator might be saying of himself and the other members of his fight club, "We had some inner demons, and becoming capable and confident in some kind of physical competition was enough to help us banish them."
That is a far smaller and simpler message than "Becoming capable and confident in some kind of physical competition grants a sense of overall sufficiency and contentment in life."
Tangentially, the trailer spoof Jane Austin's Fight Club is terrific. And someone created a Fight Club in 15 Minutes that did a great job of summarizing the film version of the story.