Dear Grandparenting: It looked like grandson Hal had the whole world in his hands at 15. You name it — most popular, leader of the pack, voted class president, the one everyone thought could do no wrong.

More times than I can remember the parents of his high school classmates told me Hal was headed for stardom. That was then. They don’t say that anymore.

Hal is 23. The golden boy has lost his glow and the cool and easy confidence that went along with it. It was like a row of dominos falling, one thing after another.

He didn’t have a plan after high school. He started running with some older kids who were house painters. He had some substance abuse issues. I bailed him out after one arrest for stealing beer. He lives in California doing “odd jobs” last I heard.

If this can happen to Hal, it can happen to anyone. Maybe he figured he was too cool or too big to fail. I know I was wrong assuming Hal would straighten out, since he’d been such a star before. Goes to prove you can’t take these things for granted. Fran Bell, Pittsburgh, PA

Dear Fran: We’ve seen this before, children who are fast out of the gate only to slip and lose their way. And socially precocious youth – cool kids like Hal – are at greater risk for such a tumble than garden-variety kids, according to a study in the journal Child Development.

Trouble can begin when youngsters like Hal decide they’re ready for the big time and socialize with older kids, apt to indulge in “pseudomature” behavior – drinking, drugging and womanizing.

Busy carousing, they don’t learn the values held by socially mature teens – supportive friendships, hard work and responsibility. When their peers were asked to score how well former cool kids got along with others, they ranked 24% below average.

Grandparents should reinforce aspects of character that help grandchildren suppress urges to be too fast, too young. Youngsters at peace with just being themselves are cool in our book.

Grand remark of the week:

Belle Jones from Dayton, Ohio tells all her grandchildren, “the price of admission to Granny’s house is a big hug and a big smile.”

Tom and Dee and Cousin Key

Dee and Tom, married more than 50 years, have eight grandchildren. Together with Key, they welcome questions, suggestions and Grand Remarks of the Week. Send to P.O. Box 27454, Towson, MD, 21285. Call 410-963-4426.