I was a barista at Starbucks and I meant every word of my greetings. The 5 seconds you make eye contact with someone and say hi to them are vital for gathering your senses, and starting this interaction a new. If you didn't say "hi, how are you", asshole clients would rub off on you and you would smear that bad vibe on all subsequent clients. However, when you greet someone, and they greet you back warmly, crap-vibes get washed away and you get good energies.

I used to look forward to my favorite clients; it's like stones in a puddle, you jump from one to the next to get to where you're going. Same with good people, they help you go through the day. So start the day positively, greet everyone cheerfully, serve loyally and enjoy yourself; the 8 hours pass QUICKLY.