In April 2011, Adele did her first cover interview for Rolling Stone Magazine. Her face on the front was refreshing: messy hair, simple make-up, her eyes staring straight into the lens. Her look said, powerfully, Babe, you can't fuck with this. The piece began joltingly, too, in a Hamburg park with her dog. “Aw, Louis!,” she groaned. “Don't roll in the shit!”   We found out inside that she had started smoking again, her long-lost dad having recently reappeared, her gran having been ambushed at a bus stop for an interview. Adele was also still in love with the man who inspired her new album, 21. What would happen to her music if she was happy, though, the interviewer asked. "No music! My fans will be like, 'Babe! Please! Get divorced!”, she laughed. “[But] don't worry. My bubble always fucking bursts.”   21 was three months old at this point, and had sold 3.5 million copies. Today, it's sold over 32 million. Why? Ah, solving that question brings the A&R and the record company boss and the strategist and the critic in their long coats running over the fields. Possible reasons are legion. Perhaps, in troubled times, people reach for comfort and warmth, and those qualities nestle in Adele’s voice, whatever you think of it. An instrument very much in debt to American soul, it nevertheless pays no dues to Mariah Carey-style melisma, or hides its owner's glottal stops and Tottenham tics. It feels different.

It feels real too, as does Adele, in a pop culture riddled with flamboyant fakery. Also, what a story to rally behind: a working-class only child of a teenage single mum goes to Fame School, and makes it. There was a time before she had negotiated difficult second album territory with more ease than most, though. If you remember it with any clarity (I vaguely do, it’s my ‘job’), you may recall it came out only two months after Endlessly by Duffy, the other husky youngster hoping for similar success this time round. Both young women were exhaustively (and exhaustingly) compared to each other back then, but crass comparisons aside, you knew Adele wouldn't sack off her management on a whim like Duffy did, or ride bikes on Diet Coke adverts. She'd be in the pub with her bosses, sloshing back the full-fat red stuff after sloshing Jack Daniels in, both feet on the table, telling bikes to fuck off. These things help.

Adele became properly huge, though, because of the connection she made to ordinary people through TV – a strategy well-worn since Ed Sullivan nabbed The Beatles, and maybe an even more powerful one now, when communal watching experiences are more precious. Watched by 14 million viewers in the middle of the 2008 US presidential campaign, this girl in a cardigan was number 40 on iTunes before performing; a day later, she was number one. UK TV also made 21, courtesy of astonishing performances of 'Someone Like You' on Later With Jools Holland, and at the Brits. On the former, she fiercely sang "never mind" while wagging gun-fingers at her ex, then promised to find someone else, before visibly welled up. On the latter, she was spotlit in the overwhelming darkness of the O2, making the weary resignation of lines like “I wish nothing but the best for you” emotional dynamite. And then she finished, bit her lip, rubbed her hands down the sides of her skirt, and we all exhaled with her, and for her.   And now here is 25. The woman behind it is in a very different place. She has a nearly-three-year-old son with a solid, long-term partner. She has long ditched the fags. She’s had another, even better "babe, you can’t fuck with this" Rolling Stone cover. She is massively famous, and rich. Her album's first single, 'Hello', also did two sly, clever things: it reminded us of the heavy, sad power of that midnight-blue Adele piano, while making subtle references to recent years, and how its singer's life had changed. "I've forgotten how it felt before the world fell at our feet," she sings in the second verse, meekly. "Hello from the other side," she sings in the chorus, more boldly. 

'Hello' begins 25, as it should, but then everything else follows. On paper, it was exciting stuff: collaborations with Dangermouse, colossal pop architect Max Martin, and 70s-obsessed indie singer-songwriter Tobias Jesso Jr. Damon Albarn had also been tried before being dropped, although we all know there was no love lost there (he called her insecure, she railed at his rudeness). Still, there would be enough meat here to chew on, for sure.

But as I listened, I kept thinking: what is it that we want 25 to do? Ideally, for this fan, something old and something new. But if you're someone like me, 25 isn't what you want it to be.

My frustrations lie here. Around the edges of every Adele album has been the glimmer of a girl wanting to push the boat far out, to do something much brasher and bolder. That feeling was there, with a bang, from the start of 21. 'Rolling In The Deep' and 'Rumour Has It' arrived full of swampy Southern soul, a style Adele had fallen in love with while on tour of rural America, sitting in the front of the bus, cadging Marlboros from the country music-loving driver. The rest of 21 veered off into Ballad Central quickly, but there was something else before that, something spiky to hang your hat on.  

    Then there were the covers Adele chose for her records. On 21, there was 'Lovesong', which she recorded in LA while missing her Cure-loving mum, and Bob Dylan's 'Make You Feel My Love' on 19 – songs she gave a new freshness and light. The interesting glimmers were there, too, as far back as her 2007 debut single, 'Hometown Glory', the small story of a sad girl roaming the streets, getting stopped by someone who wanted to help her, the city air being "so thick and opaque”, while she contemplated the dark, rheumy “wonders of my world".

You'd think that with the weight of success behind her, Adele could, and would want to, do anything. Instead, she largely retreads the same paths and explores the same tones.

After the gorgeous greeting of 'Hello', we leap to the Max Martin co-write 'Send My Love (To Your New Lover)'. Writer of tons of pop canon classics like Britney Spears’ '...Baby One More Time' and Kelly Clarkson’s 'Since U Been Gone', this is a weirdly grating piece of perky pop, perched on top of your dad’s idea of a funky acoustic guitar line. It bears the same sentiments as 'Rolling In The Deep' – an old lover can go screw himself – but none of its force.

Adele also sings in the chorus about how "we aren't kids no more", and not for the first time; 25 keeps despairing, constantly, at what it's like to lose one's youth. In 'Hello', we were told “it's no secret that the both of us are running out of time”. On 'When We Were Young', a ballad tailor-made for 2am on Magic FM but without the requisite gin-drizzled stardust, or the proper parts of speech, “we were sad of getting old”. On 'Remedy', yet another solemn piano workout, “I remember all of the things that I thought I wanted to be.”

Perhaps this constant worry about being old is a curse of their writer being in her dewy mid-20s. (In mine, I remember feeling utter failure that I hadn't done what I wanted to yet; at 37, I shake my head at my silliness, and given that the years makes you care less, in some ways, I feel younger now, somehow.) More crucially, I wonder if this is also about Adele trying to find things to write about and getting stuck. She is famously private these days, as any sane megastar should be, and doesn’t mention her partner or her child or her life in her interviews. But she still wants to write songs full of emotional weight – it’s what she’s good at – so she writes about the biggest feelings she experienced before recent years.

Sadly, this means the ex that haunted 21 is still here, like a ghost who won’t go, his gown stuck in the door. "I’ve been by myself all night long / Hoping you’re someone I used to know"... "It matters how this ends" ... "I will leave my heart at the door/I won't say a word/ They've all been said before"...if you were this man, you’d surely be thinking, Christ, 30 million records, universal adulation, love and a kid...it’s time to let it go. Similarly, listening to this album is sometimes like listening to a friend who you’ve helped countless times but who won’t listen, who actually enjoys being in a mess, whose sparkle gets dampened – gets drowned – as a consequence.

Sadly, the music is often boggy too. 'Water Under The Bridge' is a wet, mid-80s soul-stew of cliches. 'Love In The Dark' sounds like it’s ended quickly with both parties asleep. 'All I Ask' poses no interesting questions, and offers no revealing answers. Sadly, I fear, Mr Damon Albarn was right.

There are a few moments of relief, however – three to be precise. The best song by far is 'I Miss You', another collaboration with long-time writing partner Paul Epworth. It begins with the mysterious, electronic clamour of voices, heavy synth drums, and textures that wouldn't be out of place on a Burial record. Woozy gospel backing vocals then prop up a tune crying out for an epic club remix; it remains a song laden with mum-pleasing yearning, but driven in an interesting new way.

Then there's 'Million Years Ago', done in the style of a chanson, which suits Adele well; stripped of the requisite layers of tragedy, she’d make a great Cockney Edith Piaf. The lyrics intrigue, too, as they sound intensely personal. “Deep down I must have always known/ That it would be inevitable/To earn my stripes I’d have to pay/And bear my soul” – there’s what the audience have always loved about Adele, and what has become harder to give. Walking around the streets "where I grew up and found my feet/They can’t look me in the eye", she continues. "I feel like my life is flashing by/And all I can do is watch and cry.” The most affecting lines, to me, are these: “I miss the air, I miss my friends, I miss my mother." Oxygen, company, family. Fame thins them all. This is someone writing about this stuff in an affecting new way.

And then there’s 'River Lea', a song named after a stretch of London and Home Counties water that will not translate well to America, unless an enterprising soul comes along and starts up some boat-based Adele tours. Co-written with Dangermouse, a collaboration which once again sounds more thrilling on paper than it is through the ears, it shows us a little more of the girl we want to know. "My heart is a valley," she sings. “It's so shallow and man-made/I'm scared to death if I let you in that you'll see I'm just a fake." Confessing shallowness? That’s interesting. There is also an apology made "years in advance" for hurting her lover in the future, from someone basically saying any relationship of hers is doomed to fail.

And what’s to blame? The River Lea, the River Lea, the River Lea: something in the roots, in the veins, of her Tottenham past, perhaps, maybe those lost friends, that lost father, the simple connections between a person and place. Electronic gurgles and echo surround these insinuations. When Adele gets deeply personal, her status as an artist really takes flight.

But perhaps it is churlish for us to think that this soulful girl always has to sing her mind to us to connect with us. Maybe many of these songs are based on fiction these days, and millions of people won’t mind, either. They will buy 25, and use Adele as a comfort and relief and as a beautiful means of expression of their ultimate moments of sadness once again. They will be happy for her to exist in this sad place on record, pretending that the bubble she discussed years ago will keep bursting. Still, it says a lot about the modern record industry that Adele’s success hasn’t properly freed her up in the directions that always seemed to be there. I for one miss that fire starting in her heart, reaching a fever pitch, bringing her out of the dark.