Seashell

Seashell

(alt-text)

This is roughly equivalent to 'number of times I've picked up a seashell at the ocean' / 'number of times I've picked up a seashell', which in my case is pretty close to 1, and gets much closer if we're considering only times I didn't put it to my ear.

What If? is now on YouTube!
Check out the first video for the answer to
“What if we aimed the Hubble Telescope at Earth?”
and follow xkcd’s What If? The Video Series channel to be notified about each new video.