This is Tuesday, just under three weeks before his wife will be getting married, and a few days before Silver will tentatively decide that life isn't necessarily worth living when you've been doing it as poorly as he has.
-- Silver (Chapter 1 paragraph 1)

Importance: This is the introductory sentence to the novel and it seems to sum up the bulk of Silver's problems.

Yes, he is living in an efficiency hotel. Mistakes.
-- Silver (Chapter 4 paragraph 6)

Importance: This is Silver's statement about his living situation as he enumerates for the reader his many mistakes since before his divorce.

And all the while, that stick of doom in her sweaty hand, taping the podium as she turned the pages, and the thing inside her, that convergence of lust, apathy, and biology that even now must have been splitting and multiplying in her uterus like there was no tomorrow.
-- Casey (Chapter 5 paragraph 21)

Importance: Casey describes her state of mind as she read her valedictorian speech moments...