Are you a Mary Poppins, a Mr. Hyde, a Nutty Professor, or an Ernest Hemingway? You know when you’re out with your friends at a bar, and you’ve all had the same amount to drink, yet one friend is giggling uncontrollably, another is telling a hilarious story to a group of strangers, a third is picking a fight with the bouncer, and the last is talking to the bartender as if those four Jägerbombs never happened? You might have wondered, well, what’s up with that?