Smiling is infectious, you catch it like the flu,
When someone smiled at me today I started smiling too.
I passed around the corner and someone saw my grin
when he smiled I realised I’d passed it on to him.
So, if you feel a smile begin, don’t leave it undetected.
Let’s start an epidemic quick, and get the world infected!
I thought about that smile, then realised its worth
a single smile, just like mine could travel round the earth.
(Spike Milligan)