What I learned from a stranger at the Metro gate in Panama City

I had an empty card and a line behind me at the Metro gate in Panama City, and I was trying to remember my pin for the top up machine. A woman in front of me turned around, tapped her own card on the reader for me, and walked on without a word. It was the quickest kindness I have had in this city. I have repeated it twice for other people since. Both times they looked at me exactly the way I looked at her. Both times I walked on.