Since it first began in 2016, Better Things has been slowly becoming one of the finest comedies on television, but it has always been resolutely un-flashy in its brilliance. Partly that’s because its subject matter is contained and domestic, and because, in a typical episode, not very much appears to happen at all. Pamela Adlon, who writes, directs and stars, has fashioned a gorgeous and loosely autobiographical story about a raspy-voiced single mother, Sam, who is a jobbing actor, and her three daughters, living in Los Angeles. It touches on elements that are at once familiar - ageing, mortality, how women and men relate to one another - and gives them all new powers.

The show was created by Adlon and her one-time close friend and collaborator, Louis CK, with whom she shared writing duties. But, as the second season ended, and allegations about CK’s behaviour began to surface, it seemed for a moment as if Better Things could become collateral damage, caught up in the fallout of its association with him. In the aftermath, Adlon severed ties with CK and with the manager they shared, Dave Becky. In an interview with the New Yorker, Adlon said she didn’t know if she could continue with the show, whether her heart was still in it or not. Happily for fans of this beautiful, affecting series, she took some time to work it out, hired new co-writers, and got on with the job.

It feels apt, given that the show is so often about Sam having to do just that, whether that is work, or raising her daughters, or looking after her increasingly forgetful mother. She may find any given situation tough, but there is rarely an option of simply giving up. “There is a mountain of mom shit I have to do every day,” she tells her doctor, when he tries to espouse a “let it go” approach to life’s stresses. For her, letting it go is just not possible, but she finds a remarkable amount of warmth in getting by.

The third season of Better Things finds it in better shape than it has ever been. The first two episodes are directed and written solely by Adlon, who shares writing duties as the season progresses. As Sam’s eldest daughter Max moves away to college, Sam wonders why she’s putting on weight. Then, there is a brief, terrifying brush with mortality. A lesser show would have made that the focus, or at least drawn it out beyond a few scrappy minutes. But Adlon’s scenes all end where in any traditional series, they might just get going, leaving the impression of snippets of life that ultimately all carry weight of some sort. In one moment there’s a joke about vanity, and getting carded; in another, a near-death experience. Life is busy. Things happen.

This has always been a comedy that has dared to try things out. Last season, Sam, feeling underappreciated by her children, staged her own eulogy, so they could talk about how much they loved her. As a concept, that sounds cloying and self-involved, but if Adlon ever dangles her storylines close to those edges, she yanks them right back with a pithy line, or another abrupt end to a scene. Instead, the fake funeral was gentle and moving and hilarious, because Better Things is sentimental without ever being trite, and, by contrast, painful when it should be soothing.

Mikey Madison, Pamela Adlon, Olivia Edward, Hannah Alligood and Celia Imrie. Photograph: FX Networks

It feels even more unencumbered by propriety or expectations this time, not least in Celia Imrie’s portrayal of Sam’s blunt mother and nextdoor neighbour Phil. Phil’s memory continues to decline and, again, on almost any other show, this drama would be front and centre, but here, it’s around the edges where the stories really happen. Phil neutralises a tense family argument with a well-timed fart: “Oh dear, I’ve made a pong.” When a pair of exes explain their new house-sharing arrangement, she chimes in: “Sounds awfully complicated. In my day we just stayed married and had affairs.”

As the more viral corners of the internet know, children swearing unexpectedly can be hilarious. When Duke and Frankie’s bickering becomes unbearable, Sam tells them to let it all out: one minute of open, unmonitored hatred before civility is re-established. Frankie yells grievances about the perfection of her younger sibling, but Duke unleashes a torrent of creative filth that would make Selina Meyer blush. It is one of the funniest moments I’ve seen in a comedy in a very long time. And then, just like that, as the kids do, we move on.

Better Things is often discussed as a show that paints an honest and raw portrait of motherhood, and of the complicated relationships between daughters and mothers, at any age. It does that, wonderfully, but there is a newfound confidence that takes it to a different level. Where the show explores the mundane, such as a school activities’ day, or a list of household expenses read from a credit card bill, it also revels in the surreal: Sam’s dead father is a recurring character. This is the charm of Better Things. Just when you think you know what to expect, it takes a different path.