Smiling at strangers
When I was a first-year medical student, my classmates and I used to go down to the hospital cafeteria between lectures to buy snacks. The women from whom we bought them at the check-out counters were all young and sullen, rarely even glancing up at their customers as they rang up purchases. Their customers, in turn, seemed equally uninterested in them. So I decided one day I was going to get them to smile each time they rang up my purchases. To do this, I decided I'd simply start smiling at them myself.
"Hello!" I started saying each time I'd approach. At first, they actually shrank from me physically. But within a few days, they started to smile back at me. And as time passed and I continued to smile and say a bright hello each time I came before them, I noticed something interesting: most of the time they were still wearing the same lifeless expressions. I'd become their "on" switch. Their focus was so concrete that to the person in line right before me they remained their same apparently disinterested, unhappy selves. But as soon as I entered the narrow band of space immediately before them, their eyes would suddenly light up and their mouths would curve into a smile. And I could tell, though we never exchanged any words other than "hello" and they knew absolutely nothing about me, that they were genuinely glad to see me.