Well my recently single, beautiful, close friend rang me the other day, talking about the 3 P's from a book she highly recommended 'Act Like a Lady, Think Like a Man'. They are Provide for, Protect and Profess that you are theirs. So if you don't have all three – well it looks most likely that the relationship will not go anywhere so you may as well get out now. Love vs Infatuation: So how do we know we are infatuated? The chemicals are serotonin and dopamine.