For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
You can't tickle yourself.
29
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
It takes approximately 12 hours for food to entirely digest.
93
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13