I indulge more deeply in Christmas nostalgia with every passing year, but it turns out that doing so is a good thing.

“Nostalgia,” according to Merriam-Webster, is “a wistful or excessively sentimental yearning for the return to some past period or irrecoverable condition.”

Time is certainly irrecoverable. I wish I’d known, when I was child, that time would go by so incredibly fast – which makes me now long for my past.

I remember vividly one Christmastime Saturday when I was 5 or 6. It was uncharacteristically warm for Pittsburgh – so warm, my mother opened our living room windows, allowing a fresh breeze in.

I sat by those windows, waiting for my hero – my father – to return with our Christmas tree. Trapped in a kid’s time warp, minutes ticked by like hours.

In future years, I’d be his sidekick as we shopped for the perfect tree. But it was too early for that yet.

Eventually, our white Ford station wagon pulled into the driveway, a big, thick evergreen tied to the roof. As my father got out and began untying it, I ran outside to help.

He was in his early 30s then, his hair black as coal. He stood nearly 6-foot-2, a powerful man. In an era when children argued that “my dad can beat up your dad,” my dad could.

I marveled as he set the tree on the living room platform like it was a stick. Then he kissed my mother, as he did every single time he walked through our front door.

This memory still fills me with a deep sense of security. How blessed I have been to be part of a large family, imperfect as it was and still is, with my parents together, doing their best to sacrifice for and love their children.

I re-experience the deep sense of the security they gave my sisters and me when I watch “A Charlie Brown Christmas,” “How the Grinch Stole Christmas!” and “Rudolph the Red-Nosed Reindeer.”

All were huge childhood events, which my family gathered around the television to watch with Snyder of Berlin potato chips and French onion dip, a special treat in our home.

For years, according to Dr. Max Pemberton in the Daily Mail, psychologists warned against such nostalgic indulgence.

But Constantine Sedikides, a Southampton University professor, says they got it wrong. Sedikides, who researches the effects of nostalgia, argues that nostalgia can comfort people, helping them connect and cope with adversity.

Nostalgia, writes Pemberton, can “imbue us with resilience by reminding us that we possess a store of powerful memories and experiences that are deeply intertwined with our identity.”

Scratchy old Christmas albums, luminaria lining the streets, Christmas Eve gatherings with our longtime next-door neighbors the Kriegers, bittersweet memories of so many people no longer here – this is the nostalgia that holds more power over me each Christmas season.

It makes me hold doors open for strangers, give more to those in need, try to be more understanding and gracious toward those with whom I disagree.

These are the benefits of Christmas nostalgia.

May you and your family – and our country as a whole – enjoy an abundance of those benefits this year.

Tom Purcell, author of “Misadventures of a 1970’s Childhood,” a humorous memoir available at amazon.com, is a Pittsburgh Tribune-Review humor columnist. Send comments to Tom at Tom@TomPurcell.com.