It's the most wonderful time of the year, right? Jack Frost is nipping at your nose, the turkey is roasting in the oven and your neighborhood is aglow in festive lights and holiday cheer.

So how come you're so miserable?

You may be experiencing the "holiday blues," a combination of sadness and stress that affects many people this time of year, beginning with Thanksgiving and ending around New Year's.

A major contributor to the "holiday blues" is the unrealistic expectations many of us have of the holidays, due in no small part to movies, television and advertisements.

Hollywood has long portrayed the winter holidays — particularly Christmas — as a time of magic and wonder ('It's a Wonderful Life' and 'Miracle on 34th Street' are two examples). This creates a fantasy to have a sort of Norman Rockwell experience.

But when our lives, sometimes messy and complicated, don't match these media messages, it's easy to feel that we have failed in some deep and meaningful way.

"We have such high anticipation for the holidays and very unrealistic expectations," says Atlanta psychologist Marjorie Blum. "It leaves us with this feeling of dread when our idealized views are not met."

Instead, Blum notes, "we need to expect imperfections in events and in ourselves, and expand and develop new traditions."

Tradition and expectation are often intertwined at the holidays, and when the two are at odds, it's easy to become frustrated or disappointed.

"We have traditions we like to follow at certain holidays and when someone wants to deviate, it gets those who want to retain them bent out of shape and uncomfortable," says Jannette Robert Murray, a psychotherapist in Spokane, Washington.