People don't just mysteriously wake up one morning with an overdose of PEA in their brains and then develop a crush on the next person they set eyes on. No, PEA and its sister chemicals are precipitated by emotional and visceral reactions to a specific stimulus. Like what? It can be a whiff of her perfume, the boyish way he says hello, or the adorable way she wrinkles her nose when she laughs. It could even be an innocuous article of clothing you're wearing that drives your Quarry bonkers. What really makes one fall in Love?