The smallest actions can set off a chain of happiness. if people give just a moment, or just a small gift, then perhaps that chain of kindness will continue.  Take a look at what happens to this construction worker…who unknowingly sets off a chain reaction.  

Be sure to watch it to the end.  Trust me, it will complete you.

And maybe today is a good day to start your own chain reaction. When someone does something as simple as smile at you, pay it forward.