A book about nothingness I read in 2006-2007. Quote about "fish finding food all day for the energy to find food all day."

[Reader]

I’m 31 years old now but waaAaay back when I was 12-14 years old I read a profound book I found at a secondhand store. It was kind of a book about nothingness. I vaguely remmeber the main character going to fight in a way but not much else. I know distinctly a bit about “fish finding food all day for the energy to find food all day” and also a woman in the story deciding not to love the main character anymore because it was too exhausting. Please help

[Robert]

The Society of Others has this line: " Fish swim about all day finding food to give them energy to swim about all day."

[Kris]

Google Books preview of The Society of Others by William Nicholson - Robert's suggestion:

- https://www.google.com/books/edition/...
- There are different cover images.