It’s the same absurd episode every year. About a week into their winter break, my children take on the properties of common pond leeches.

Lazing around in their pajamas day after day, they suck down eggnog and cookies ’til the gifts come, then invariably whine about what they don’t have: the proper batteries, the money to buy what they really want, the opportunity to see that dreadful chipmunk movie …

That’s when I lose it. That’s when I go into self-righteous harpy mode, decrying their ingratitude and asking if they know what “entitlement” means and how profoundly unattractive it is. The lecture ends when I get to: “Why are you so spoiled?” Because the answer is a neon billboard-sized arrow pointing directly to their spoiling, entitled mother.

I admit it. I’m not the very model of magnanimousness, not the emblem of altruism. Sure, I leave pantry booty at the mailbox for canned food drives. I lower my window at off-ramps to toss a Washington to the fella with the pleading eyes. But I ain’t what you’d call a giver.

I’m well apprised of society’s ills; I’m just not accustomed to asking, “What can I do to help?” And much as I want the world to be a better place, I’ve never felt capable of making it so.

I know families who volunteer in their communities as regularly as they get haircuts; it’s part of their routine, like brushing teeth, paying bills, or anything else that isn’t pure mirth but is ultimately more appealing than the alternative.

“Service” wasn’t one of my family’s values growing up. My grandparents were immigrants and struggled just to take care of themselves. But the “every clan for himself” notion is too easily, and imperceptibly, handed down through generations, until some of us find we have everything we could possibly need — except for the tiniest shred of graciousness.

So when my sixth-grader piped up with his frickteenth post-holiday bellyache, I knew I had to do something momentous. Not another feckless lecture or empty threat. No guilt-eliciting “you hurt my feelings when you fail to appreciate my efforts” gripe. This had to be in-your-face, off-our-butts effective.

So I dragged him to the local homeless shelter to serve lunch to a couple hundred down-and-outers. It was new to both of us. And tremendous. For both of us.

My philanthropic friends have long known what we didn’t: that giving your time, your muscle, your smile to a strapped stranger sets your soul upright. That it’s less an onus than an honor.

“It feels great relieving someone else’s struggle,” explains a friend in Kansas.

“These are the things that make your life worthwhile,” echoes a Colorado mom.

“I find,” admits a California gal, “that by giving time to others, I am less focused on my own whines.” Best news of all: It applies to your kids’ whines, too.

“What can we do to help?” we asked as we entered the shelter. They tossed us aprons and put us to work on the buffet line handing out day-old bread and pastries donated by area markets. Some of the guests carried IV bags and had lesions. Some were better dressed, better groomed, and undoubtedly better mannered than us.

“Would you care for some bread, ma’am?” I got to ask a woman who did indeed care for some bread. “Can I offer you dessert?” my son got to ask a man with a passion — and a giddy grin — for cobbler. It wasn’t remotely heroic, what we did. It wasn’t hard. Ultimately, it might even have been selfish, since we left feeling crazy-good about ourselves.

Because we did make the world a better place. For that moment, for those people.

We can’t wait to go back. We’re spoiled.