I heard that I knocked on the door three times before I went to Thailand to stay in a hotel. Why?

Be polite and pray. Thailand is a Buddhist country and believes in ghosts and gods. When you enter a hotel room, you should tell the people inside in advance in case there are "aborigines". Sorry, I'm only staying here for XXX nights, so I won't disturb your rest, and then you can live in peace. Actually, it doesn't have to be for non-believers. There are many tourists in Thailand, and they are slowly opening up.