Smiling Is Infectious

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 realized,
I'd passed it on to him.

I thought about that smile,
Then I realized its worth.
A single smile, just like mine,
Could travel round the earth.

So, if you feel a smile begin,
Don't leave it undetected.
Let's start an epidemic quick,
And get the world infected!