There’s some history hovering over Forward Theater’s production of Amy Herzog’s “4000 Miles.”

Like, literally hanging above the set, in the form of framed photographs of early 20th Century storefronts and brownstone apartments from Greenwich Village, where Vera (Susan Sweeney) a feisty nonagenarian, has lived the bulk of her life. Not that that history means much to her twentysomething grandson, Leo (Mitch Bultman), who unexpectedly shows up on her doorstep late one night, fresh off a countrywide-spanning bike ride that’s left him both scarred and directionless.

Vera’s a little directionless too, her life devolving into newspaper crossword puzzles, grocery runs and waiting for her circle of aging friends to shuffle off the coil. Over the course of this light and lighthearted play, they’ll annoy each other, surprise each other and learn from each other.

Leo’s the sort of all-too-self-aware youngster most parents recognize all too well. He’s got a kind, sweet, nature, but he’s also entitled and overconfident—as becomes apparent when he characterizes the fact that he’s not currently speaking to his mom as being “at a juncture.” Bultman plays him with a gentle, desperate sweetness: His scenes with Bec (Rachael Zientek) , the ex-girlfriend who’s plodding through college in New York an effort to move past Leo and get on with her life, show there’s real pain and feeling under the self-absorbed façade.

Sweeney expertly captures her character’s frustration—at her surprise house guest, and at her memory’s failing ability to remember the words she wants to use. But there’s also a hard-won wisdom shining through that enlightens the other characters.

Of course, it’s the shifting interplay between the family generations that holds the production’s humor and appeal. He talks about power, she talks about progressivism. He annoys her by breaking faucets, she annoys him by relying on the Yellow Pages instead of her underused Macbook. Eventually, they’re celebrating the autumnal equinox by sharing a joint and oversharing their sexual histories. You know, the usual grandmother-grandson discussion-type thing.

There are points in the play that almost seem too consciously quirky, like the circumstances of the tragedy that changes the nature of Leo’s cross-country ride. Leo’s scene with Amanda (Lucy Tan), a potential one-night stand, is both hilarious and revealing—interesting that she resembles Leo’s adopted sister, Lily, isn’t it?--but it also feels like it’s been stitched into the proceedings from a different play, just to break the claustrophobia.

Conversely, the play’s payoff scene couldn’t feel more intimate. Sweeney and Bultman are pitch-perfect as they sit on the couch in the darkened apartment and Leo finally unburdens himself of the details of what happened on that fateful bike ride. Even here, Herzog manages to leaven the proceedings with knowing humor.

“4000 Miles” is the sort of quirky/touching family comedy Forward’s made a specialty of in recent years (Think “from Up Here” with fewer characters and lower dramatic stakes), and there’s a genuine warmth that comes from watching these two characters move beyond their self-imposed prisons toward understanding, self-awareness and new possibilities. It’s that feeling that lingers.

“4000 Miles” runs through Nov. 20 in the Playhouse at Overture Center.