If you really want to freak someone out, ask the man or lady at the toll booth "How are you?" with a smile. It has to be the worst job in the world.

I make it a policy to compliment children - "You have the prettiest hair", "That is a great jacket." Always a sincere observation. Brightens them right up and Mom too. Or just take a look at a child and smile at Mom. Says it all.

People "know" me where ever I go in my neighborhood or where I work because I always smile and say "Hi!" There's an ongoing feud between the people in my office and a repair shop across the street over parking. But all the men who work there wish me a "Good morning", ask about my family...It is so much easier to be friendly than to scowl and act superior. Treat people with respect an friendship and they respond.
On the other hand there is our mailman...