In Night by Elie Wiesel, why was celebrating Passover like playing a comedy?

In Night, the celebration of Passover was comic because people pretended to be happy.  

Wiesel shows the comedic aspect of Passover in Sighet.  Everyone played their traditional part in the festivities.  The weather was "sublime" and women like Wiesel's mother were "busy in the kitchen" as synagogues were closed. People met in "private homes," ensuring not to "provoke the Germans." Everyone in Sighet portrayed their part dutifully in this comedy.

However, it was clear that they were acting.  This attempt at comedy belied the Nazi presence in Sighet.  People were avoiding what was in their hearts: "We drank, we ate, we sang. The Bible commands us to rejoice during the eight days of celebration, but our hearts were not in it. We wished the holiday would end so as not to have to pretend."  Their acting was an attempt to deny or evade the bitter truth of Nazi occupation.  

Wiesel makes it clear that the comedy of Passover celebrations came to a tragic end on the seventh day as "the curtain finally rose" when "the Germans arrested the leaders of the Jewish community."  The Passover celebrations showed how the people of Sighet pretended to be happy.  The celebrations were an attempt at comedy in a world mired in tragedy.