In Night, why is Elie ashamed of his own behavior?

There are many points in the novel Night
in which Elie is ashamed of his behaviors. It all stems from the theme of
survival and the animalistic instincts that come out in men when they are 1.) trying to
survive and 2.) being treated like animals for so
long.

Being treated like animals starts right in section
two when they are carted to Auschwitz on cattle train cars. They are huddled together in
masses, terrified of what is coming next and because of the women who keeps yelling that
she sees fire. The first shameful incident is when the woman on the train is gagged and
beaten into submission. Elie can't but help feel relieved that she is no longer able to
scream and terrify the others.

The most intense feelings of
shame and guilt occur toward the end of the novel when Elie's father is close to death.
He has dysentery, and he refuses food and water except for when Elie forces him to take
it. Elie resents his father and even contemplates stealing his father's ration of food
and water for himself. He resists the temptations.

Elie
fakes sick to stay with him during the days because other men beat him and steal his
food and water during the day when Elie was gone. One night, Elie's father calls to him
from his bunk, but Elie is tired and sick of taking care of such a burden. He ignores
his father, and is horrified to find his father's bunk empty when he wakes
up.

Elie never knows whether his father was even dead when
the guards took him in the night and threw him in the crematory. But Elie doesn't feel
sorrow or fear at first, instead he just thinks "I am free at last." This immediate
thought makes Elie feel truly guilty for not being there when his father was dying to
protect him and hold his hand as he passed.