If you went biology in high school, you know that your brain is made up of different centers that control different parts of your body both mentally and physically so it would come at no surprise that there is an area of the brain that has a "holiday center!"
So what is a "holiday center"?! According to Bustle, there was a study done in Denmark in 2015 that found that different parts of your brain lights up when thinking about special holiday memories, traditions and so forth are brought up and compared to stuff from the rest of the year.
"Throughout the world, we estimate that millions of people are prone to displaying Christmas spirit deficiencies after many years of celebrating Christmas. We refer to this as the 'bah humbug' syndrome." However, the study itself revealed some deeply intriguing things about how Christmas affects the brains of those who have no deficiencies of Christmas spirit at all."
Kind of interesting huh?! It totally makes sense now!