No one really knows where the heart symbol comes from, but there are theories. One is that the heart shape comes from the shape of the leaves of a now-extinct plant called silphium, which was considered a key component of a love potion in the time of the Romans. Another theory is that St. Valentine used the symbol when arranging secret marriages. Another is that it was simply a guess of what the human heart looked like.

Love and other emotions are actually regulated in the brain, not the heart. Specifically, a part of the brain called the amygdala.

People might partly associate the heart with strong emotions like love because when we get excited to see someone, our heart sometimes beats faster, and we notice our heartbeat. We aren’t really aware of what’s happening in our brain.

The human heart pumps blood to all parts of your body. The heart beats once a second. If you live to the age of 70, your heart will have beat about 2 billion times!