For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Chewing gum boosts your brain power.
285
The average person's skin weighs twice as much as their brain.
131
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your heart will pump about 212 million liters in its lifetime.
26
Poor eyesight (myopia) is associated with higher IQ.
232
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22