A reason from Million Reasons

“My father z"l who was the only survivor of his family (49 perished השם ינקום דמם) was constantly making jokes to his fellow inmates in the 5 years (3 different concentration camps) that he suffered under the Nazis ימח שמם וזכרם. When his friends asked how he could joke in these terrible times, he said "I want to outlive Hitler ימח שמו and that's how I'm going to succeed" - ותשחק ליום אחרון. If that could be done during WW2 in Birkanau, Buchenwald…”