To numb the shock of the conditions at the concentration camp, and to increase the chances of her own survival, Hannah imposes upon herself the command "Don't think.  Do" (Chapter 12).

Hannah, who has been transported back in time, knows the full implications of what is happening to the Jews in Poland during World War II.  She tries to warn her relatives and the people of the village, but no one will listen to her.  When the Jews are indeed arrested and taken under horrendous conditions by boxcar to the camp, she continues to try to make them understand that the Germans are going to kill them, but Gitl tells her to allow them to continue to "live moment by moment", because "what is here is bad enough".  Upon reflection, Hannah realizes that "her knowledge of the ovens, of the brutal guards, of names like Auschwitz and Dachau" can do nothing for them "except to take away that moment by moment of hope".  She resolves to stop thinking about what she knows, to just live in the moment, and to do whatever is necessary to survive (Chapter 11).

Hannah makes two other promises to herself in the camp.  She resolves with Gitl never to cry, because by not crying she is stronger (Chapter 11).  And she promises to remember, no matter what happens, whom she is and what has happened.  That is all she can do, for herself and those who will come after (Chapter 12).