When I was a wee lad in elementary school, I was fascinated to read about the origin of the modern “heart” shape, which looks nothing like the anatomical human heart. It all goes back to Saint Valentine, the Xian martyr, who was locked up in prison, and sent notes of love (presumably agapeic love, not erotic) to his fellow Xians. Since he didn’t have any paper, he wrote on leaves which were shaped like what we now think of as a heart.
I thought this was so cool that I made valentines out of green construction paper that year. My classmates already thought I was weird. This merely confirmed it.