I was 7 years old when I received a tiny Christmas present -- about the size of an eraser -- awkwardly wrapped and covered in tape. My sister's boyfriend, Jeff, was visiting and had considerately brought gifts for his girlfriend's three younger siblings. Mine, though, was by far the smallest. I remember opening it up to reveal a miniature ceramic dog -- a cold, hard nothing that fit in the palm of my hand -- and thinking how unlucky I was. I gave Jeff my best cold shoulder the rest of the day.

And I've felt guilty about it ever since. Partly because, in hindsight, Jeff's gift was very thoughtful: I'd been obsessed with my dollhouse, and he had managed to find one accessory my dream home did not yet have -- a pet. Still, I couldn't look past the size of the gift to be grateful for the amount of care that had gone into choosing it.

In this, experts say, I wasn't an unusual kid: For distractible, still-developing children (and that's pretty much all of them), gratitude can be hard-won. While many can be trained to say "please" and "thank you" beginning at about 18 months, true appreciativeness and generosity take time to seed and blossom.

"There's a difference between encouraging thankfulness in your kids and actually expecting it," says Claire Lerner, a child-development specialist at Zero to Three, a nonprofit organization dedicated to the healthy development of kids and families. "Raising a grateful child is an ongoing process."

Vicki Hoefle, director of Parenting on Track, a parent-education program based in East Middlebury, VT (and the mother of five teenagers), concurs: "As nice as it is to think about having a five-year-old who appreciates and shows gratitude for everything, the truth is, parents can feel successful if they raise a thirty-five-year-old who embodies that grateful spirit."

So, to Jeff Galvin I offer a long-overdue "Thank you." To everyone else, here's how to avoid getting derailed by five not-so-thankful-kid moments, both this holiday season and all year long: