Rivers Cuomo is running on empty. Waxwork pale, his skin glistens with something deeper than exhaustion. He holds himself creepily still, like a lizard on a branch. Behind vast, black-rimmed spectacles, pinprick eyes dart constantly. They remind you of searchlights, probing the sky.

What, you wonder, is he looking for? This is a question we may not have time to answer. In the parlance of his adopted south California, his issues are waaaay metaphysical dude.

Cuomo, it immediately becomes apparent, would rather be anywhere but here. You shouldn’t take that as a slight. It’s not you he wants away from. It’s himself. Escape – a repudiation of reality – is a recurring trope of Weezer, the proudly awkward indie rock foursome he’s truculently fronted for the past decade.

Self-loathing riddles his songwriting, imbuing Weezer’s bouncy melodies with an undertow of toxic anguish. Cuomo pisses in the punch-bowl of pop-rock and asks you to drink deep. Don’t worry, he seems to say. It still tastes mainly of fruit juice.

Today, however, there are only flickers of Rivers Cuomo, post-grunge angst-child. Mostly he’s a walking power failure, a blackout in scuffed chinos and polo shirt.

We are perched backstage at Vicar St. in Dublin, several hours before Weezer are due to play their debut Irish show. The prospect does not seem to electrify the singer.

Howling silences strafe our conversation. When, eventually, Cuomo speaks, the words emerge in diffuse trickles. In a single sentence, he will, a dozen times, lapse into indecipherable mutterings. Is he talking to an invisible chum at his shoulder?

“Meditation…“ – who’s asking about meditation!? – “Yeah... I’ve been doing.... a lot of that recently. It....brings me to a...(extra long pause)....place, y’know? Helps me feel free.”

Throughout our exchange, Cuomo reveals himself to be a serial abuser of monosyllables. “Um” is a favourite. He’s a devotee, too, of “er”, and a tapering “well....” Occasionally he’ll adjust his spectacles and regard his sneakers (fans will be interested to know they are old-school Converse, black trimmed with laces of radioactive white). Such didactic tics are deployed as bookends, framing those inevitable, baffled squalls of quietness. Frankly, you’re starting to feel like a waiter who has lingered too long after pouring the wine.

Interviews, one guesses, cast a wintry spell on Cuomo. Outside the interrogation chamber he passes for nearly normal.

As we walk back to the singer’s dressing room a little later, for instance, I will remark that several of my friends are huge Weezer fans and have, for months now, been looking forward to tonight’s show. And, almost like a regular person, Cuomo will smile and say, “well, great!” and sound as if he means it.

The problem, he eventually admits, is that people insist on treating him too seriously. Fans applaud sarcasm where none exists.

Cuomo insists he isn’t an oracle, a lightening rod for suburban angst. He’s just a short guy in a plaid shirt with a knack for upbeat/downbeat pop-rock.

“The weird thing for me is that people hear irony and sarcasm in my music when there isn’t supposed to be any,” he says (further pauses have been edited out for the reader’s sanity). “A lot of my early songs were really, really heartfelt. Everybody thought I was joking! I found that hard to deal with.”

He cites ‘Beverly Hills’, a riff-heavy single from Weezer’s new album, Make Believe, as a case of mistaken irony. Against a juddering pseudo-metal back-beat, Cuomo serenades the world’s most famous post-code, a place where life is soft and the bodies hard.

“For me it was a straightforward song. Beverly Hills seems like a really great place to live. But it was misinterpreted as some sort of sarcastic commentary or something. People just think too hard about pop songs. Aren’t we allowed to be throwaway anymore?”

Thinking too hard has sometimes been a problem for Cuomo, also. Three years ago, while frantically embracing a life of rock-star cliché, he was struck down with an existential crisis. There had been profligacy – booze and groupies, though little drugs – and excesses of ego. One morning, he was violently sick of both.

“I needed to stop being that person, y’know? Not because it was wrong but because – and it took a while for me to realise this – an ego is the biggest menace to a songwriter. It can destroy you. It takes away your ability to step outside of yourself, which I feel is important if you want to make music that means something to people. I had to retreat to somewhere.”

For pop stars ‘retreat’, usually, is synonymous with a spell of luxurious rehab. Never one for small gestures, Cuomo put Weezer on ice, working as a volunteer with a HIV charity in Los Angeles that distributed food to homeless AIDS sufferers.

“Getting away from being a rock star was really important for me. That existence can destroy you as a songwriter in the end.”

He has proved just as extreme in his embrace of meditation. Cuomo practices an obscure discipline called ‘Vipassana’, entailing lengthy silent retreats in dark places (caves high in the Himalayas are recommended but an airtight cupboard will suffice at a push). Meditation and virtuous reinvention are familiar recourses of the jaded rock-star. Does Cuomo fear becoming a stereotype? The question fizzles in his lap like an unexploded grenade; seconds will slip by before he continues.

“I never thought of it like that. I just wanted to find a peaceful place. Meditation is a very simple thing for me. It gets me out of the prison of my head. I get to be somewhere else. I’m not sure where, but it’s a happy place.”

Two years have elapsed since Cuomo last penned a song. In the same period he has observed a vow of chastity. It strikes him as peculiar that anyone should connect the two.

“Y’know...it never occurred to me that way. But now that it does, I don’t think there is a link at all. There’s a straightforward reason why I haven’t written any songs – I haven’t tried to. I just haven’t been in the mood. It’s not complicated. Sometimes a song will come to you, sometimes it won’t. You can’t force things.”

The chastity trip he finds less easy to elucidate: “Well, people have written that it’s a vow. But I haven’t sworn on a Bible or anything (Cuomo is an occasional Buddhist). I don’t know… there are times when a thing just feels right and, for where I am now, this is right. It’s not a monastic thing. I haven’t become a hermit or anything”

How curious then that Make Believe should prove to be Weezer’s least chaste record yet. It is loose and throwaway, carrying itself with a palpable swagger. This, Cuomo believes, is down to producer Rick Rubin, who encouraged the band to surrender their quest of perfectionism in the studio.

The singer admits initially struggling with Rubin’s approach. An obsessive student of the pop form, he carries at all times a notebook of Green Day and Nirvana songs, in the hope of distilling the perfect rock anthem.

“I’ve got a scientific sort of mind. Rick is much less formal. He would tell me to go into the studio and play whatever felt right. Early on, I had certain problems with that. It was like: I can’t just go in and PLAY IT. I’ve got to think about it first.”

Propelled by an eye-popping video shot at the Playboy Mansion, ‘Beverly Hills’ delivered Weezer’s biggest hit in half a decade. While they’ve been away (Cuomo split Weezer at one point to facilitate his return to college), the scene they helped spawn has sunk into a generic fug and acquired a lame moniker: emo (hipster shorthand for ‘emotive rock’). Dropping the word in the company of Cuomo precipitates at flush of cold anger.

“Emo – what’s that about? It’s just a label. All I want to do is write great pop songs. Emo means nothing to me.”