It’s one thing to grapple with having been a one-hit wonder, and another when that singular smash may have given the world a wrong impression of what you were all about … or just represented a moment in which selling out was quickly succeeded by flaming out. These are some of the matters troubling former Chumbawamba frontman Dunstan Bruce’s mind in “I Get Knocked Down,” wherein the singer takes part as narrator, co-director, primary subject and putative conscience of a swept-aside alt-rock generation. His intention with the film is to beat himself up a little and find some redemption, proceeding from the assumption that having been responsible for 1997’s globally massive “Tubthumping” is not its own eternal reward.

“I Get Knocked Down” — named for a line in the chorus of “Tubthumping,” which will be instantly familiar to just about anyone sentient in the late ’90s — quickly emerges out of the gate as an often intriguing, sometimes unwieldy combination of two filmmaking approaches. Parts of the film are pretty straightforward rock-doc, with plenty of satisfying archival footage portraying the long rise and short-lived plateau of Chumbawamba, a collective of self-described anarchists from Leeds who aimed to mix agitprop and pop and ended up sneaking leftist politics onto “Top of the Pops” and “The Rosie O’Donnell Show.”

But the film’s beginning and ending and significant interludes in the middle are staged like an adaptation of a one-man (or two-man) show, with Bruce doing monologues about middle-aged angst, or being stalked by a sinister figure wearing a mask modeled after the grotesque baby head on the “Tubthumping” album cover. This devilish doppelganger with an electronically deepened voice keeps verbally torturing the musician with punishing reminders of how unwanted and irrelevant he is now that he’s rounding 60 and a quarter-century past having any kind of media profile. Not much is left to subtext here as the movie poses the most obvious questions, like: He’s been knocked down! Will he get up again?

Those stagey moments in which Bruce is a dapper sad-sack who’s literally confronting his inner demon are sometimes funny or trenchant, but they can also feel on the forced side. And a little of his heavy-handed narration goes a long way, when he’s reinforcing the point that “once upon a time I thought I could really change the world … but that was way back when I was someone.” But when the movie — co-directed and produced by Emmy winner Sophie Robinson (“My Beautiful Broken Brain”) — relaxes into a more traditional doc approach, it’s on surer, if less dramatic, footing. Bruce, a much more dapper and handsome fellow now that he’s gray than he was in his bleach-blond ’90s, is a very affable host as he catches up with some former Chumbawamba members to compare notes, or even visits leftist figures ranging from filmmaker Ken Loach to elder anarcho-punk-rocker Penny Rimbaud to ask them if they think he sold out his principals by having a pop smash.

These high priests forgive him of any shark-jumping sins. Rimbaud, formerly of the band Crass, assures his visitor that any pop striving was worth it for the moment when one of the members of Chumbawumba used their appearance on the Brit Awards to go over to U.K. Deputy Prime Minister John Prescott’s table and dump a bucket of ice water over his head, stirring up outrage in the British papers. There were other attention-getting stunts, like having another member go on Bill Maher’s show and suggest that members of the working class should feel free to just shoplift Chumbawamba’s new CD. The funniest archival clip may be Rosie O’Donnell expressing surprise that she’d had actual anarchists on her previous show and didn’t even know it. For anyone who wants real insight into the life, death and interpersonal dynamics of the band, that would be for another documentary, though. (And Bruce did make one on his own back when he was still in the band, 2000’s “Well Done. Now Sod Off.”)

But after an understandably long section devoted to the international success of “Tubthumping,” and how what they intended as a populist anthem was understood as a basic pub sing-along, we don’t really learn anything about how the group broke up, or even for sure that it did. (Bruce left in 2004 and the others called it a day in 2012.) Practical questions you might have about whether he makes a livable wage off “Tubthumping” royalties and syncs, when eight members shared the copyright, will not be addressed in a movie that’s more concerned with Bruce’s existential questions.

Still, you can’t have anything less than admiration for a movie in which its subject/maker films himself failing to find much of an audience in late middle age for his new endeavor, a group called Interrobang. “Your dad would be so proud of you, shouting at some people in a half-empty room!” sneers the masked figure. Better, or worse, yet is a real-life scene that reaches “Curb Your Enthusiasm” levels of discomfort when Bruce visits Republic Records mogul Avery Lipman, who was Chumbawamba’s label chief in the ’90s, and asks him to put headphones on and listen to his new band. Lipman smiles while listening to the new music and then bluffs his way out by saying he’d love to hear the group live. He surely never will, and the chummy ease with which Lipman escapes from his old comrade’s confrontational pitch makes for kind of a classic music-biz-doc moment.

Bruce is having it both ways, of course, by packing all this self-effacement into a film whose existence undeniably represents an act of ego. Regardless, his 60-ish musical contemporaries are bound to find much to identify with, as the Chumbawamba rocker emerges as — to quote an old commercial that may or may not have gotten across the pond to Leeds — the kind of Weeble who wobbles but won’t fall down.