I work from a little home/office that looks out onto the street. I love watching the world go by. Especially when curious faces catch my eye and smile.
Some people are like that, aren't they? Their smiles sit there, right beneath the surface, ready to respond to even the simplest of every.day.life.joys. Others' smiles are there [I'm sure of it] but they're packed away deeper down, not as accessible.
I think it's something you can practice [lifting your gaze, relaxing your face, expecting joy, playing with a smile...even just a little one, if it makes you nervous to begin with]. Who knows, eventually you might even become a World.Class.Smiler.
[super!]