The tram I am riding from Andel to Malestranske Namesti has stopped for a red light. Outside, I see a lady in an apron emerge from cake store and show a cake to a man who is waiting by his idling car. Looking at the cake, he appears dissatisfied. He says something, gesturing at the cake. The conversation between the two is getting quite animated. I catch the man's eye, and assure him with a positive gesture and a lick of my lips that it certainly is a delicious looking cake. He thinks for a second, and then accepts the cake with a brimming smile. Situation defused - joy spread.

A lady sitting near me on the tram has observed the whole situation. She initiates the following conversational:

Lady: How do you spread such joy?
Me: You saw that.
Lady: I did, ...
Me: That's all it takes.