Truth Quotes in Everything Is Illuminated

How we cite our quotes: (Chapter.Paragraph)

Quote #4

I manufacture these not-truths because it makes me feel like a premium person. (17.7)

Whoa, whoa, whoa. You mean people are just as much who they are perceived to be as who they actually are? Does that mean Facebook is a lie??

Quote #5

Once you hear something, you can never return to the time before you heard it. (18.22)

What has been seen cannot be unseen, and what has been heard cannot be unheard. A good pair of noise-canceling headphones might help, though.

Quote #6

"I used to think that humor was the only way to appreciate how wonderful and terrible the world is, to celebrate how big life is. You know what I mean? […] But now I think it's the opposite. Humor is a way of shrinking from that wonderful and terrible world." (18.27)

Jonathan's view on humor changes as the novel progresses, and he starts seeing humor as a way of lying, or skirting the truth. Is this why the book becomes way less funny toward the end?