When the moon is full, you might find yourself sobbing over your first love on the couch. What made you think that? Research dating back to 400 B.C. blamed behavioural changes on the moon's pull. After all, the term "lunatic" was derived from the idea that "mental state changes were related to lunar cycles," according to Healthline. Perhaps this is why, in Shakespeare's Othello, Emelia tells Othello that the moon is too close to Earth, and has driven men insane.