At the grand old age of 29, Kevin Bridges thought he had reached the end of his career. The Scottish comedian had completed his third arena tour, selling out 180 nights. “And I probably could have chucked it and moved into something else,” he says. “I just felt a bit unhappy. I had stopped enjoying it, to be honest. You don’t want to be the guy who’s annoying people. I don’t want to be on the telly all the time. I was just burned out. And I had nothing else going on in my life. I’d split up with my ex and I was just doing the gigs and coming back home to an empty house. I just thought: ‘Right, maybe this is the end. It’s been a great 11 years.’”

If a mid-life crisis and retirement plan at 29 sounds a little premature, everything about Bridges’ career has been similarly precocious. He first performed in a Glasgow comedy club at 17, before he had ever seen a live standup routine; by 18, he had reached the final of So You Think You’re Funny? at the Edinburgh fringe; at just 22, made his BBC One debut on Michael McIntyre’s Comedy Roadshow. Within hours, his entire Edinburgh festival run had sold out and since then he has become a regular fixture of TV comedy panel shows – Have I Got News For You, 8 out of 10 Cats, Mock the Week – and a staple on the TV chatshow sofa. He is great friends with Frankie Boyle, he has performed for Barack Obama and his sweary, observational humour invariably draws comparisons to his idol – and now big fan – Billy Connolly. Still in his 20s, was he seriously ready to walk away from all of that?

“I enjoyed the travelling, the freedom, the novelty of not having to be at an airport or check out of a hotel at a certain time. But after a few months you almost start to miss it – maybe not the travelling, but the shows and strangely the nerves themselves. Everyone needs a structure in their lives to be content, and I think I missed that. I had been playing squash, badminton, five-a-side football, going jogging, drinking, but it was all ‘resistance’, to quote The War of Art by Steven Pressfield.” He laughs at himself: “I was reading self-help books, too! I was in a dark place.”

‘My girlfriend will never accept that lying on the sofa in my World Cup 1998 Brazil shorts staring at the ceiling is me being creative’ … Bridge in 2012. Photograph: Anthony Upton/REX/Shutterstock

Bridges says he spent most of his first decade in tears, weeping hysterically every time his mother disappeared from sight. But if his 10-year-old self was still a lot like a toddler, in his teens he seemed to leap a generation, and critics have always agreed, at least, that his style is mature. Has he always felt out of kilter with his age? He nods. “Everybody’s got an optimal age and I think I was never suited to being, like, 15. I had mates who were just cooler. They were better at football. They were better with girls. They were more popular. Then you see them now and they’re just a bit … well, they were great at being 15, but they’re not so much now. I think everybody’s got a peak age – and I think I always felt a bit older.”

He puts this down to having a brother who is 10 years older than him, whom he idolised and who introduced him to older tastes. “At the end of the school disco, they’d bring in the Spice Girls or whatever, the Smurfs song or whatever. I’d be bringing in a Stone Roses album. I just grew up appreciating old stuff.”

Bridges’ candour is one of the many reasons why almost half of his new 70-date tour in the autumn has sold out already. To his fans, he feels like one of their mates up on stage – and his performance persona is indiscernible from the one I meet in a London bar. The cliche of the morose off-duty comic is off the mark; he has that mysterious gift of making you want to laugh by his mere presence, but he is also intently engaged, leaning in as we talk, as if eager to connect. The simultaneous impression of bulletproof self-belief and self-aware humility is winning and inextricably Glaswegian.

Bridges’ humour is rooted in working-class Scottish self-deprecation; one of his early routines riffed on Glasgow being branded Europe’s murder capital and voted the UK’s friendliest city “in the same week” and featured a skit about the people there being nice, “bit mental, but a friendly mental”. To be a Glaswegian star, therefore, brings its own problems, celebrity being antithetical to the culture of the city. The downside of overnight stardom, I suggest, must have been the challenge of remaining connected to this rich seam of material. He thinks not.

“At age 17, to attempt standup comedy, it takes a bit of either bravado or just 17-year-old ego. You just don’t care. You’re young, you’ve been chucked out of school, you’ve nothing to lose, really – and that carries you through, so you go on stage so confident. Then you start going: ‘Fuck, they’re paying me money for this,’ and you start taking it as serious as I should have took my school work. Then it gets to the stage where you go on TV, the general public start enjoying it, they want to buy tickets. The workload becomes so big that I think it forces you inside yourself to go to, like, the self-doubt. I’m going: ‘Fuck, I’m selling this many dates, you need to deliver.’ You know, this is going to be my fourth big tour. I could be up in Glasgow walking about being the man – or I could come down here and get in the gym, you know. They call it the gym – that’s the new material, the open-mic nights and all that.”

Work ethic seems to be Bridges’ solution to the complications of fame and informs a lot of his conversation. The night before we meet, I saw him in the “gym”, when he performed a “work in progress” show at the Soho theatre. Like all great comedians, his performances convey a casual effortlessness that belies a marathon slog of rehearsal and precision tuning; the show allowed a glimpse into that process. Some jokes bombed, others took unexpected detours; at moments, as Bridges made notes, he looked almost vulnerable. “But you deliberately bring it down a level,” he explains, “because if it’s just laugh, laugh, laugh, the temptation is not to try out the really raw stuff. You’ve got half-baked ideas but you think: ‘Oh fuck it, I’m going to regret going home knowing I never at least tried them.’”

He grew notably impatient with one particularly rowdy audience member, reminding me of a news report in 2015 that he had hired a security detail to clamp down on hecklers at his shows. Was that true? “No, that’s – aye, well, that’s a different way of wording it,” he offers dryly. The problem, he explains, isn’t hecklers, but wildly drunken audience members who just roar at almost everything he says. “What people don’t realise sometimes is that, you know, in Glasgow, we done 16 nights and that’s 180,000 tickets. So if 1% of them are arseholes, that’s 1,800 arseholes. That’s a lot. It’s a vocal minority, but it gets a bit … when somebody’s just shouting ‘Kevin!’ or just shouting old fucking jokes – they just shout anything. It’s not even heckling. Aye, and it’s like they don’t realise that every single night there’s one of them, so maybe that’s where the frustration comes some nights. It gets a bit frustrating if somebody’s all about themselves.”

The contemporary impulse to make everything about oneself exercises Bridges a lot. He mentions the decision of some independent booksellers to remove David Walliams’ work from their shelves following the infamous Presidents Club dinner that the children’s author hosted. “He never groped anybody. He just took the booking, so what is behind this? Are they just trying to get their bookshop in the paper and a pat on the back? It’s all: ‘How can I make this situation about me?’ It’s all about me.”

He often lampoons the narcissism of Facebook and he grows practically evangelical about Chris Rock’s decision to ban smartphones from his latest tour. “Usually, I wouldn’t go to the bar at a big event, because I would just be getting mobbed. But there, everybody was still coming up and talking to me, but they don’t have a phone, so you actually talk to people. Normally people are just going: ‘Kev, fucking selfie,’ and they don’t even talk to you. It’s just like you’re getting passed around a wee bit. Aye, and it’s probably better for them because I think if you walk into a show or the cinema and turn your phone off and lose yourself in something for a couple of hours, you walk out feeling amazing. At the Chris Rock gig, ask anybody who was there, it was brilliant just sitting and watching something. You’re not telling people you’re there, you’re just going: ‘This is happening right now. I don’t care what’s happening anywhere else.’ Aye, it was brilliant.”

Bridges has been with his new partner for nearly two years – a restaurant manager in Glasgow who “works, like, 12-hour shifts. Unthinkable! So I think that motivates me to work harder – even if she’ll never come to accept that me lying on the couch in my World Cup 1998 Brazil shorts, staring at the ceiling, is me being creative.”

Bridges still lives in Glasgow, but when I mention something he said in 2013 – “I don’t think I’d be funny if I lived in London” – he looks unsure. “Again, that changes with growing up. I thought I wouldn’t be funny because I needed to stay one of the lads – but your life moves on. You don’t want to be the guy who’s still talking about being ‘one of the boys’ and all that. I still go back to Clydebank, to the local pub occasionally, but then it gets a bit like …” The sentence tails away. Like an affectation?

“Aye. Exactly. You’re not moving on. You think, why am I still drinking here? Not in a bad way. But why are they still drinking there? I don’t think that because ‘I’m Kevin Bridges’. It’s just because I’m 31.”

Kevin Bridges: The Brand New Tour opens August 2018. For dates, see www.kevinbridges.co.uk