When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
You forget 90% of your dreams.
256
Your fingernails grow faster in summer.
744
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22
The human eye blinks an average of 4,200,000 times a year.
233