when chris came from the war, he felt ashamed because --------------------

Chris said to Ann that he almost felt ashamed to be alive. Because he has seen so many dear men die, while people in the State related to the war as if it were a "bus accident" - at first you say "oh how sad", but you don't really care and you don't really want to care because it doesn't seem like that big of a deal.

Also, he felt ashamed to have everything he has - car, home, money, Annie - because during the war he had understood that it was loot, it had blood on it.