It reminds her of those dreadful sorts who used to go around announcing “I’m a people person,” as though one had another choice. - Judith Martin

The reason for not announcing a new job until it is time to give proper notice of leaving the old one is always that it had not yet become “definite.

Yes, indeed. “Good morning” is an opener, and “Good day” is a closer.

Without such rules, there are no exchanges of ideas, only exchanges of set positions and insults. People who disagree rapidly move from talking over one another to shouting one another down, and from expressing their opinions on the matter at hand to expressing their opinions of the intelligence and morality of those who disagree with them.