"Don't introduce yourself, act like you were in the room all along." This surely is a good advice from someone in the room greeting someone who just entered.

"Don't introduce yourself, act like you were in the room all along." This surely is a good advice from someone in the room greeting someone who just entered. It's called a protocol. Assume "hello" means something. https://www.youtube.com/watch?v=Unzc731iCUY https://www.youtube.com/watch?v=Unzc731iCUY