For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
Chewing gum boosts your brain power.
285
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Every year your body replaces 98% of your atoms.
119
Your heart will pump about 212 million liters in its lifetime.
26