Why North Korea has banned citizens from drinking, laughing, grocery shopping for 11 days?

North Korea bans laughing: North Korea has banned its citizens from laughing, drinking, and going grocery shopping for the next 11 days starting from December 17, 2021. As per the orders, people in North Korea are not supposed to show any signs of happiness for 11 days. Even if a family member passes away during this time period, no one is allowed to cry out loud.

source https://www.jagranjosh.com/current-affairs/north-korea-bans-citizens-from-drinking-laughing-grocery-shopping-for-11-days-1639741240-1