There are novelists who seem to spend their entire careers either apologising for being themselves or trying to become someone else entirely. And then there’s Dave Eggers, who has spent much of the last quarter century trying – and, it has to be said, as far as one can tell, very happily succeeding – to become Dave Eggers. Ever since A Heartbreaking Work of Staggering Genius appeared in 2000, fulfilling almost entirely the audacious promise of its title, Eggers has occupied that peculiarly American position of being not simply Yet Another Novelist, but the Guy, the Man, the yardstick by which all others might be judged and found wanting. He’s a publisher, campaigner, literacy activist, editor, artist, children’s author, philanthropist and impresario. Not only is he the Guy – worse, he seems like a thoroughly nice guy.

Contrapposto, his first adult novel for several years, and, we’re told by the publishers, ‘20 years in the making’, is another worthy addition to the vast Eggers canon. Having long since abandoned the pyrotechnics and performative cleverness of some of the early books, he is now busy pondering the meaning of life.

Having abandoned the pyrotechnics of his early books, Eggers is now busy pondering the meaning of life

The book’s ostensible subject is art and the art world. Robert Dibb, referred to throughout as ‘Cricket’, discovers very young that he can draw – and, more importantly, that drawing gives him a way of being in the world. The book basically consists of a chronological account of his life, from childhood to old age, focusing on various key episodes which illustrate the nature of friendship, ambition, disappointment, etc. A portrait of the artist as a young man – and a middle-aged man and an old man.

Cricket’s relationship with Olympia – variously known as Pia, Limpy and Lim – who repeatedly enters and leaves his life over the decades, provides the book with its emotional and narrative architecture. Olympia at times comes a little close to being a Manic Pixie Dream Girl, ‘a sorceress and all the world’s storms combined and contained’. Nevertheless, their friendship has the nice, grainy texture of actual friendship: the misunderstandings, absences, irritations and the inexplicable loyalty. Plus, they occasionally have hot sex. (‘Made a mess of you again,’ says Pia.)

The title is a clue to the book’s central concern. Contrapposto is the classical pose in which the body’s weight rests unevenly; balance achieved through asymmetry. The novel is interested in exactly those slightly off-centre arrangements that constitute any adult life: art vs commerce; solitude vs companionship; talent vs discipline. Few of us – even the mighty Eggers, presumably – ever stand entirely upright.

Of course, the trouble with art about artists – novels, films, plays, take your pick – is that it tends to oscillate between reverence and satire. Either art redeems everything or artists are insufferable frauds; or, occasionally, both. (For a recent example, see Ian McKellen’s Lucian Freud-y turn in The Christophers.) Fortunately, Eggers has more than enough experience of the creative industries to avoid the easy and the obvious and focuses instead on the stubborn human need to just make things, however foolishly.

I won’t reveal the plot but suffice it to say that success in the end for Cricket is entirely beside the point. Fame, after all, is fleeting. Markets fluctuate. Reputations evaporate. The making alone remains: the colour harmonies, the pigment loads, the work.

The book’s greatest strength is undoubtedly Eggers’s understated comic gift: it’s almost as if every page ends with a little raised eyebrow and a shrug. There are wonderfully observed scenes in art schools, galleries and at exhibitions, where everyone is trying, with varying degrees of desperation, to appear as though they understand what the hell is going on.

There are also a couple of weaknesses. First, there’s the determination carefully to observe and note everything, as if the writer were a painter, which at times veers close to self-parody:

Silas’s twin bed was next to his chair. Usually the bed was tidy, befitting a former navy midshipman, but today it lay unmade, the plaid wool blanket still at a ragged diagonal.

Eggers certainly knows how to paint a scene, but there is such a thing as too much information.

The second problem is the book’s sheer scale. Four hundred-plus pages is a generous canvas for any artist. Occasionally that generosity becomes a little diffuse and blurry: certain episodes feel less dramatically necessary than emotionally necessary for the author. A self-portrait of the artist, perhaps – in a very large, convex mirror.

Still, the overall effect is both deeply pleasing and delightfully, depressingly true to life: the fond recounting of old, odd, pointless conversations, embarrassing enthusiasms and people who disappear for 20 years and then unexpectedly return. Like contrapposto itself, the novel finds its balance by refusing easy symmetry. It leans a little one way and then the other; off-centre, out of kilter, alive.