One time in South Dallas a bird pooped on my head.

I thought it was a raindrop, which looking back seems odd considering every pigeon in the metroplex was hovering over me. Sweet hindsight. Always 20/20. 

As I talked with a woman on the sidewalk, I casually swept over the raindrop with my hand. 
By swept I mean smeared.  And by raindrop I mean bird poop.