In January of 1990, almost twenty years ago, I pitched a joke in the writers' room of TV's long-running, phenomenally popular comedy Cheers. The actual joke is forgotten – it wasn't a good one (I didn't pitch anything good, or even decent, for a while) but I was young, and it was my first real job, and so I knew about what someone who was twenty-four and starting his career knows, which is to say, nothing...