A human brain produces as many as 12,000 to 50,000 thoughts per day, depending on how deep a thinker a person is.
23
Human hair and fingernails continue to grow after death.
7
Enamel is hardest substance in the human body.
61

Mushrooms are more closely related to humans than they are to plants.
47
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Tigers can see 6 times better at night than humans.
305
You can't tickle yourself.
29
Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21