3 We only use 10 percent of our brains.

Neurologist Barry Gordon told Scientific American that humans "use virtually every part of the brain" and most of the brain is "active almost all the time."

4 George Washington had wooden teeth.

It turns out our nation's first president wasn't rocking a pair of wooden chompers. The historians at the Washington Library say that while George Washington did suffer from dental problems, his dentures were composed of ivory, gold, lead, and even other human teeth—but never any wood.