STUART Braithwaite, musician, front man of Glasgow post-rock titans Mogwai and now published author can sum up his working life in seven little words. “Being in a band,” he tells me, “is patently ridiculous.”

It’s a Wednesday morning and Braithwaite is in Govan helping his wife out on a video shoot – “being a runner, lifting stuff about”. But he’s taking a break to talk about Mogwai now and then, his wild new memoir Spaceships Over Glasgow and the inherent and aforementioned ridiculousness of life in a band.

“Lots of funny things happen,” he continues. “I guess it’s a bit of a contradiction because our music is super-serious. But pretty much everything apart from the music is just nonsense.”

The music is, of course, the important bit. Mogwai are now the elder statesmen of the Glasgow music scene. They’ve 10 albums to their name and more than a quarter of a century making music on their CV. Last year’s As the Love Continues album proved that age hasn’t wearied them. It was the band’s first number one and was shortlisted for the Mercury Prize.

Next week the band will play Christmas gigs in Scotland, including two nights at Glasgow’s Barrowland, with a tour following in the New Year. February also sees the reissue on vinyl of debut album Mogwai Young Team and its follow-up Come On Die Young to mark 25 years since the release of the former in 1997.

In a way this year has been a time of taking stock. The most obvious result of this is Spaceships Over Glasgow, a book that charts how a boy’s all-consuming passion for music took over his life and shaped it more than he could have imagined. It’s also a moving tribute to his father, although Braithwaite admits that hadn’t been in his plans initially. “The influence my dad had on my life really came through when I was writing. That wasn’t a point I set out to make.”

It also contains some teenage cross-dressing, UFO spotting, Blur-slagging, fights with city traders and Braithwaite’s use of The Herald newspaper as a cure for homesickness when he lived in London.

Mostly, though, it’s an account of excess and the consequences that arise as a result. Describing the end of one chemically-assisted tour, Braithwaite writes that “we’d accepted chaos as a lifestyle choice”.

Reading the book, I tell him, I am sure I experienced a contact high and felt its queasy after-effects. There are a lot of very messy days and nights charted in its pages.

“That lifestyle is very much in the past for me,” Braithwaite points out, “so it’s more a sort of chuckling eye-roll about what I did. I tried not to throw too many people under the bus, which led a lot of people to think I was the most mental … Which was not true by any stretch.”

Yet at one point, I say to Braithwaite, you do admit you thought one of your hands was possessed. “That was quite a weird period in my life,” he admits. “Not a very long period, but quite a memorable one. Stories are never black and white … I was going to say on the one hand … On one hand, that was one of the most exciting times in the band. We had signed to a big label, we were recording in New York. On the other side, I was totally freaking out and probably someone should have sent me home to drink tea and toast for a couple of weeks to calm down.

“I spoke to our old manager because he’s read the book and he said at the time we probably knew all this but it was the way things were rather than any kind of problem.

“Thankfully I just got myself together and it was all fine, but in the music industry some people don’t get it together. There’s an awful lot of terrible mental health issues in the music industry. It’s something that people take seriously now, but it was something that back then no-one even thought about.

“I’m not the first or last musician to freak out while making an album, but hopefully people take care of people better than they did back then.”

Whether the road to excess leads to the palace of wisdom, as William Blake suggested, is maybe not clear. But it’s worth noting that Mogwai weren’t the only ones walking it. Arab Strap and Primal Scream, it’s clear from the book, lived the rockstar lifestyle too. Braithwaite also reveals that Elastica were the hardcore party animals of Britpop.

“And the only ones with the decency to not reform,” he points out approvingly when I bring it up.

That’s as sharp as his tongue gets today, but like he says, he has calmed down. The days of Mogwai band merchandise including T-shirts with the motto “Blur are S****” (NB, the asterisks are ours) are behind us.

And all these years later that build-them-up-knock-them-down tribalism that marked the music culture the band grew up within has long disappeared.

“It has,” agrees Braithwaite, “and I feel in two minds about it. Because it’s intensely petty and to a 20-year-old now describing a lot of this stuff would just seem demented. But, yeah, people lived and breathed and chose who they were through what music they liked.

“I do miss the nonsense of it,” he adds, but suspects Mogwai still wouldn’t be around if that tribalism was still in place. “In the olden days we would long have been shuffled into a cupboard and replaced with a new, shinier model.”

Mogwai’s story reminds us that the 1990s were never just about Britpop. But it’s a story that continues to the present day. The success of As the Love Continues last year shows Mogwai are as relevant as ever.

“We just never expected to have a number one record. It wasn’t even a ‘Oh it would be nice if that happened’ kind of thing. It really came as a massive surprise. It was great. We really felt a lot of love around the release. It was a difficult time during lockdown and people really missed music. We were all missing concerts. It was nice to feel the support. It was a special thing.

“I’m just looking forward to making another one now. I think that’s our plan for next year.”

What, I ask, did he learn about himself from writing the book?

“What did I learn about myself? I learned that I could put my mind to something that would have seemed preposterous not that long ago. In fact Lee Brackstone, the publisher had actually asked me if I wanted to write a book five or six years ago and I literally laughed when he said it. It was the least likely thing. I’m the kind of person who has a panic attack if I have to write anything longer than a two-line email. I learned that I’ve got a level of perseverance that I didn’t think I had in me.

“There’s a level of vulnerability in doing something in your mid-40s that you’ve never considered even doing before. Yeah, that was definitely a lesson I learned.”

And what would the teenage music fan you were think of this 46-year-old man you’ve become?

“He would be very impressed with how many distortion pedals he’d amassed,” Braithwaite says, laughing. “He’d be very surprised too. When you’re young you don’t have long-term plans. We didn’t even have a plan for an album. We’d never even thought that far ahead. So 10 albums and, whatever it is, 27 years later, definitely wouldn’t have been on the agenda.

“But a lot of the bands that I looked up to were bands who had made a lot of records, like The Cure and Sonic Youth. So he would probably be very happy to think I was following in those footsteps.”

Mogwai play Aberdeen Music Hall on Tuesday; Usher Hall, Edinburgh, on Wednesday; and Barrowland Ballroom, Glasgow, on Thursday and Friday. Spaceships Over Glasgow is published by White Rabbit, £20