The heart is a peculiar organ, so peculiar that for most of history no one knew what it did. Leonardo da Vinci, unarguably one of the smartest people to ever walk the earth, was so confused by the heart that he gave up studying it. Yes, it was that bad. And even in the 21st century, only surgeons have actually seen a working heart.

This Ted-Ed animation will clear up a lot of the mystery surrounding the heart and make you feel way smarter than you did when you woke up this morning.