Nostalgia seems to kick in earlier and younger, at least to those of us of the “St. Elmo’s Fire” or “Big Chill” generations.

Thus, the legion of 28 year-olds getting misty-eyed over high school in “10 Years,” a high school reunion dramedy full of alcohol, last chance romance, memories both bitter and bittersweet, big secrets and bigger revelations.

It’s a movie that doesn’t take its own advice — “Why spend your time looking back when you’ve got so much to look forward to?”

Writer (“Dear John,” “We Are Marshall”) and first-time director Jamie Linden traffics in the soapy, melodramatic cliches of such ensemble pieces. But with sharp casting he pulls off a movie with a dash of wit, a few genuinely poignant moments and a generous helping of grace notes to make the cliches go down easily.

Channing Tatum is Jake, the handsome, popular prom king who went on to an exciting life as a…mortgage broker. At least he has a hot, younger date (Jenna Dewan Tatum, Tatum’s real-life spouse) to drag with him to Lake Howell High’s tenth reunion.

Anna (Lynn Collins of “John Carter”) shows up alone, the popular party girl from way back still pursued by guys like Marty (Justin Long) and his married pal AJ (Max Minghella). Anna still lords it over the once unpopular kids.

“Yes, I had a much better time in high school than you did.”

Chris Pratt is aptly cast as Cully, the ex-jock and “reformed” bully who married Sam (Ari Graynor), had kids and adopted a sweater vest as his new uniform. He drinks too much and tries to make amends to everybody he picked on way back when.

“I owe you and you and you and you and you an apology.”

Reeves (Oscar Isaac) became a pop star, but still crushes on Elise (Kate Mara). Garrity (Brian Geraghty) is married to Olivia (Aubrey Plaza of “Parks & Recreation”), but never told her about his days as a high school hip hop wannabe.

“You married a WHITE girl, for real?” cracks his old pal (Anthony Mackie).

And the list goes on.

It’s easy to see how Linden attracted such a star-studded young cast. Most every character has his or her own moment, and many of them deliver lines that stick with you, having a hint of profundity to them.

“Can you imagine NOT being disappointed at prom?”

“You date who you’re supposed to date in high school, not who you really like.”

The “big reveals” won’t shock anyone, but they are so well-played that they still manage to move — the love affair, undimmed by the years, the wounds that a decade hasn’t healed, the disappointment at the way life has turned out.

“10 Years” doesn’t reinvent nostalgia and doesn’t do enough with the concept of “the road not taken.” But if enough years have passed for you to miss those days, it’s worth breaking out the rose-colored glasses for.

MPAA Rating:PG-13 for language, alcohol abuse, some sexual material and drug use

Cast: Channing Tatum, Ari Graynor, Jenna Dewan-Tatum, Justin Long, Chris Pratt, Anthony Mackie, Aubrey Plaza

Credits: Written and directed by Jamie Linden, an Anchor Bay release.

Running time: 1:40