A fatherless kid and future writer comes of age in the working class Long Island of the ’70s and ’80s, mentored by an autodidact uncle in “The Tender Bar,” a film based on a memoir by J.R. Moehringer.

It makes a fine vehicle for Ben Affleck, as the bartender-sage father figure, and for Tye Sheridan as the kid who gets into Yale and gets published. Both actors giving their warmest performances in years in a film by a director who’s lost his fastball, and can’t get his curve over the plate much either.

Whatever George Clooney saw in this tale of a kid “raised” by an uncle because his father is a drunken, self-absorbed lout of a disc jockey, he and Oscar-winning screenwriter William Monahan, — utterly lost without his screenwriting crutch, heated cell-phone arguments (“The Departed,””Body of Lies”) — are barely able to assemble this, with “memoir” their sole organizing principle.

Starting at point A (1973) and at point C (the early to mid 1980s), with both ends of a flashback working towards the middle, the film blows its “Eureka!” moment, loses track of its central relationship and fills the screen with life lessons and waypoints so banal as to make one grateful you’ve never heard of the book it’s based on.

“When you’re 11 years old,” our adult narrator (Ron Livingston) tells us in the weariest “Wonder Years/Goldbergs/Everybody Loves Chris/Arrested Development” fashion, “a guy could use an Uncle Charlie.”

In 1973, little J.R. (Daniel Ranieri) and his mom (Lily Rabe) are doing what “everybody” in their family does — “moving back home” to her parents’ house in Manhasset. She’s a single mother who’s just been evicted again, bitter about “going back” and refusing to call the place “home.” Her retired, whimsically disconnected Dad (Christopher Lloyd) takes it all in not-quite-insulting stride. His house is “overrun with aunts and cousins,” a riot of noise, relationships and crusty, bluff sentiment, all a reflection of grandpa.

But never-married Uncle Charlie (Affleck), spirits purveyor at the family bar — The Dickens — sees this as his moment to step up. Like everybody else in this family, he talks to the kid like an equally foul-mouthed adult. He sizes up J.R.’s lack of sports acumen, his need to find his “it,” whatever “it” is, and makes his promise to “never lie to you.”

He’s the one who warns J.R. about looking “for your father in the radio,” where the kid can hear “The Voice,” the New York D.J. who fathered him, is never there for him and can’t be bothered with child support. “Don’t look for your father to save you.”

As Charlie sends J.R. on “smokes” runs, sets him up with sodas at his book-covered, barfly-friendly Dickens watering hole, he sets out to teach the kid “The Male Sciences,” where to keep “your butts” (cigarettes), your “stash” (emergency money in your wallet), what to do with your liquor (“Hold it.”), to learn the essentials such as “how to change a tire and jump a car” and to “always take care of your mother.”

Before too long, J.R. settles into the books Uncle Charlie points him to “if you want to be a writer,” and the bar jargon, how to “back up” (order a drink for) his colorful, friendly fellow barflies (Max Casella, Michael Braun, et al).

Concurrently, the story jumps ahead to “I wanna be a writer” J.R. (Sheridan) as he’s heading to Yale, attending Yale, falling for the wrong woman at Yale (Briana Middleton) and in the film’s most eye-rolling touch, chatting up a friendly Irish priest (Billy Meleady) on his train rides to and from New Haven.

Every now and then, “The Voice” (Max Martini) comes back into J.R.’s life.

Clooney walks us through the waypoints and pivotal moments of J.R.’s early years with barely enough emphasis for us to have those “Wonder Years”/movie memoir cliche “That’s when I first realized” epiphanies.

Clooney half-heartedly makes points about how nothing changes in Manhasset. Fashions? A little. Relationships? Rarely. But for some reason, the cars and music never do. It’s all a hazy blur of condensed memory, being “stuck” in a rut somewhere, but still sloppy for a period piece.

We get little sense our hero is “special,” aside from an early push towards reading and a first-job-out-of-Yale with the New York Times. The “writing” and “talent” aren’t present, the distinct voice indistinct in the extreme.

But a sweet scene or light touch here and there brings us right back. Grandpa didn’t raise bookish kids by accident. Uncle Charlie has two very human Achilles heels and even the memoirist’s limitations are laid out as “I’m writing a novel” when everybody tells him publishing is “leaning towards memoirs.”

So? Write what you know, surf the wave.

Affleck finishes off a pretty good acting year that won’t earn him much credit (“The Last Duel” bombed, this isn’t a box office or awards contender). He makes Charlie colorful, dutiful and a fond remembrance of a guy who put a kid on the right path.

Young Ranieri is properly wide-eyed and angelic, and Sheridan gets to smile, something his career has rarely afforded him the chance to do.

And the setting is a Bar of the Sentimental Imagination, where even the alcoholics have a charming literary color about them.

As undemanding and shambolic as it is, “The Tender Bar” takes you in with warm afterglow and some winning, “I’d like to have a drink with that guy” moments. But even Amazon should see that after “The Midnight Sky,” “Catch-22,” “Suburbicon” and “The Monuments Men,” Clooney’s a Hollywood icon best parked in front of the camera, not behind it.

Rating: R for language throughout and some sexual content

Cast: Ben Affleck, Tye Sheridan, Lily Rabe, Daniel Ranieri, Briana Middleton, Max Martini, Rhenzy Feliz, Max Casella and Christopher Lloyd.

Credits: Directed by George Clooney, scripted by William Monahan, based on the memoir by J.R. Moehringer. An Amazon Studios release.

Running time: :1:44