Well, if u turn your head 180 degrees, it kinda looks like a heart. That's why people use it. Kidding. Nobody's quite sure, but it might have to do with a North African plant. During the seventh century B.C., the city-state of Cyrene had a lucrative trade in a rare, now-extinct plant: silphium. Although it was mostly used for seasoning, silphium was reputed to have an off-label use as a form of birth control. The silphium was so important to Cyrene's economy that coins were minted that depicted the plant's seedpod, which looks like the hart-, hart shape we know today. The theory goes that the hart-, hart shape first became associated with sex, and eventually, with love.