..because I’m a giver:
If you are an acquaintance of someone, and you happen to walk past that person while pretending not to see them, at least continue the charade until the end. Don’t turn back and look at the ignoree a second later, at the same time they are looking back at you thinking “Did they just deliberately ignore me?”
* This happened to my wife yesterday, and to her credit, she smiled and said “hello” to the acquaintance. If it was me, I probably would have helpfully suggested they do something anatomically impossible.
Which probably means Aussie Dave’s Rules of Social Intercourse: #21 is “Don’t take advice on social intercourse from Aussie Dave.”