It’s hard to make the right decision about what to study at university. Politics or politicising Beyoncé? Computer science or the sociology of Miley Cyrus? But in the US — where these pop-starry modules were once the most-booked on campus — there’s a sexy new subject slinking on to student timetables, and it’s possibly more helpful in later life.

“Adulting” — a term for learning how to be a grown-up when you’re part of the ineptly unpractical generations Y or Z — has become one of the most oversubscribed at the University of California, Berkeley. Launched by fellow students Belle Lau, 21, and Jenny Zhou, 20, the course covers subjects as un-hip as tax returns, time management and “red flags” in relationships. Yet when it first arrived, unadvertised, on the university website they had to turn people away from the 30-person class. “They were like: ‘Hey! Why didn’t I get in?’ I felt quite bad,” Lau says, on the phone from California.

This year they had more than 200 applicants for the 12-week course, which is part of the university’s DeCal scheme — classes organised and taught by students that are usually taken in the evenings on top of academic majors, which last 90 minutes and involve a speaker. Lau and Zhou now vet applications, choosing a 50:50 gender split and the students who sound like they most need help. “Someone said they wanted to understand when fruit was ripe,” Lau tells me earnestly.

Adulting classes are doing just as well on the east coast of America. In Portland, Maine, courses in DIY and looking after yourself at Adulting School are packed with men and women aged 22 to 38. About 70 per cent of attendees are female, with students taught via interactive lectures and online tutorials, ranging from £10 to £150 a session.

Someone said they wanted to understand when fruit was ripe.

Under the six class categories (DIY, wellness, money, relationships, work and lifestyle), I find a lot of anxiety-inducing suggestions of adult skills I should possess aged 29; I feel like a lazy Brownie with a bare sash. Being able to chop wood is, granted, probably more useful in freezing Portland than central London, but I can’t invest in stocks or “patch walls like a pro” either. I can’t maintain my car, because I don’t have a driving licence, and have been using feminism as an excuse not to sew for years. Every time an ex-boyfriend asked if I could mend a hole in a sock I would tell him not to be so sexist (having no idea how).

Thankfully other sections of the Adulting School website are more reassuring. A blog post on basic etiquette “never taught” in schools asks whether it’s ever “OK to post pictures of my boobs on Facebook the day before a big job interview”, which I can’t say was ever covered by my teachers at school, but I did manage to work out on my own.

Stuffed animals are soft. Life is hard. Get on with it.

I also take comfort in the herd. A study of 2,000 adults by Bupa earlier this year found that there were 40 simple things over-55s could do better than millennials aged 25 to 34. About 60 per cent of the older age group said they knew how to get stains out of clothes, compared with only a third of millennials. Twice as many over-55s could sew on a button. General home maintenance — possibly given that we are generation rent — is an obvious stumbling point.We also fared worse in first aid, shoe-polishing, understanding metric measurements and even telling the time.

Some ineptitudes I’ve seen first-hand. My former housemate, a 29-year-old engineer who could make successful million-dollar deals at work, failed consistently to order correct quantities on Amazon Pantry, and ended up once with a crate of water chestnuts instead of a single tin for a stir-fry. It took us eight months to get rid of them — only by serving them in soy sauce at parties as if they were 2019’s most fashionable canapé. I own six novelty cheesegraters for the same reason and will be giving the other five I don’t need as Christmas presents.

A blog post on basic etiquette “never taught” in schools asks whether it’s ever “OK to post pictures of my boobs on Facebook the day before a big job interview.”

Thanks to the internet and smartphone apps, some of these adult “skills” have become largely redundant. We don’t need to learn how to navigate with an A-Z when we use Google Maps; Citymapper deletes the need to read transport timetables; we can’t focus a camera because we take pictures via Instagram. Monzo — which now has more than two million users in the UK — controls our weekly budgets and monitors spending, essentially distributing pocket money in the same way our parents would have. The problems occur when our phone breaks.

Rachel Flehinger, the principal at Adulting School, believes we shouldn’t take common-sense skills like these for granted any more. “Parents often assume that basic skills are common sense, but they aren’t common sense until they are learnt and that means they still have to be taught,” she says.

“Millennials and Gen Z got caught in a shift because parents’ priorities have changed, from sitting down at dinner and talking to their kids, to keeping them busy and occupied, and on to the next ‘thing’. Both parents may be out at work all the time rather than at home balancing a cheque book or working on the car, so these are skills that young people don’t pick up now. But a smart person with questions and gaps in their knowledge finds the answers.”

Lau agrees. “People often blame their parents when they feel inept,” she says. “Either people say that their mum still does their laundry, cooks and shops for them, and as a result they don’t know what to do when they leave home. Or they say that their single parent or parents were always out working, were busy, or not at home, so they had to take care of themselves and didn’t learn basic things. At the beginning of the course, when people walk in, they breathe a sigh of relief that they’re not the only ones failing to be independent.”

People often blame their parents when they feel inept.

The emphasis is on DIY learning, which is why adulting courses are snapped up. After noticing a 15 per cent increase in searches for professionals who could talk about basic cooking and mechanical skills, money and careers, Kai Feller, a co-founder of Bark.com, a recruitment site, launched the first “adulting 101” classes in the UK last year. Starting at £50 a day, they cover skills such as how to change a tyre and apply for a passport.

“Since launching the service we’ve seen more than 2,000 requests for these skills,” Feller says. “Professionals are being hired for things like cooking classes, fixing basic mechanical problems and providing simple financial advice. We’ve even had job requests through the site in the past looking for electricians to change lightbulbs!”

Leiths cookery school, which offered an online course for the first time this year, is mopping up those looking for basic culinary knowledge. Its six-month, £1,495 course, which teaches you how to cook eggs and roast a chicken, is routinely sold out.

The overriding feeling among my age group is that there’s no rush because adulthood is still a long way off. At 30 we might once have been married, owned a house, had a car in the drive and a baby on the way but that’s not what 30 looks like any more. The majority of my friends and I are still renting; we are freelance job-changers on dating apps who live for the weekend and lack savings.

“It’s the same here,” says Lau. “We keep pushing back adulthood, thinking we’ll get a house later, a car later. No one wants to leave senior year, not because they love studying, but because they’re not ready to be set free and fend for themselves. We reach responsibility later now.”

However, like having bad teeth in your thirties, there are some things worth fixing earlier on. We should probably start telling ourselves that tax returns have never been sexier.