Want to stay current with Arthur’s writing? Sign up to get an email every time a new column comes out. If you celebrate Christmas, you might assume that the “right” way to do so is simply to let loose: destroy your usual healthy diet with a lot of sugary, rich foods; drink more wine and liquor than normal; spend loads of money. Researchers have long affirmed that many people love this abundance bordering on excess. One study from 2007 found that the most common groupings of Christmas-holiday feelings related to bonhomie, gay abandon, ritualism, and love of shopping. Even hearing “Frosty the Snowman” in the pharmacy puts people in a festive mood. But the researchers found one other common holiday feeling: “dejection.” That included annoyance, disappointment, sadness, irritation, and boredom. If that describes your state—or if you’re simply uncomfortable with the season’s overindulgence—you might feel like a Scrooge. Because the world certainly wants you to understand your reaction in this way. But your response could be anything but misanthropic. On the contrary, a rejection of …