On average, there's 100 billion neurons in the human brain.
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Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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.
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Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
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The average sperm cell swims at 8 inches per hour.
4
You forget 90% of your dreams.
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An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23