Do Christmas songs ever make you weepy? Me, too. I regularly get choked up whenever Karen Carpenter's "Have Yourself A Merry Little Christmas" comes on my shower radio in the morning. A colleague at Health finds "Silver Bells" and Bing Crosby's "I'll Be Home For Christmas" tear-inducing. As I write this, Elvis's "Blue Christmas" and "The Little Drummer Boy"—not exactly the perkiest tunes—are in the lead for an AOL voting contest on Best Christmas Song.

I also wanted to cry when I heard Wham's "Last Christmas" played for the bazillionth time, but that's another story.

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Music has strong ties to memories. Research shows that a hub in the brain's prefrontal cortex which stores memories and controls emotion lights up when familiar songs are played, hence your weepy reaction to hearing a holiday song that your dearly departed granny played during your childhood.

Yet a recent study in the journal PLOS ONE found that sad music can make us happier, too, because it evokes complex yet positive emotions—most commonly, nostalgia—along with feelings of peacefulness, transcendence, and tenderness. Which explains those warm-fuzzies that flood through me as I'm standing in the shower.

Now I need someone to explain my obsession with that video of Mariah Carey singing "All I Want For Christmas Is You" with Jimmy Fallon and The Roots. I think it's the guy playing the toy xylophone.

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