The beautiful and ancient Japanese art of kintsugi refers to the craftsmanship of mending broken pots with gold lacquer. The eye is drawn to the cracks (or "scars") filled with gold – to the bits that were broken, the bits that are far from perfect. It’s this that makes the pots so beautiful.

At my school, we have done a lot of work on failure, on building grit and resilience, adopting a growth mindset and all the other terms that have almost become clichés. And yet, perfectionism still rears its head from time to time. Clever and hard-working students, in particular girls, cling to it.

But, actually, it’s the adults in the equation who need to be reminded of a sense of perspective. It’s parents who swoop in and want to save their children from failure, getting down in the trenches with them, seeking to resolve their friendship issues, explain away the late or undone homework or blame poor teaching for their child’s lack of focus or success. This week, it was even reported that parents are paying for tutors to help them understand their children’s homework.

The result? Children who are so over-parented that they struggle to individuate at all. These teens have no skill in forming their own narratives, in finding and using their own voices, in coping with their own disappointments, in making their own plans or devising their own dreams. This extends way beyond school.

Schools now have to manage the parents

There are parents supporting their children with their university assignments; using the wonders of WhatsApp and Skype to listen to lectures alongside their kids – poised and ready to assist in the dissertation editing to come. It takes helicopter parenting to a terrifying level. Schools, and indeed universities, are finding themselves spending almost as much time managing parents as teaching their children.

I can remember being in no doubt that my parents (themselves both wonderful educationalists) would rather run down the street with nothing on than complain to my (or my siblings’) schools about any concern they might have had. It honestly would not have crossed their minds – not least because they were very clear that school was our business and our job – they were only tangentially connected to it. This did not mean that they didn’t care. Far from it, they sacrificed a huge amount to pay for our education from their teachers’ salaries. They knew the value of education and its significance – but they recognised, as many did at the time I suspect, that being educated partly meant learning to deal with things that don’t always go your way.

Pupils need to be able to accept that things can’t always be perfect – a successful and good life is led by people who can take responsibility for trying to make things generally better, rather than by endlessly voicing discontent about the things they don’t much like.

Our children are growing up in a world in which unrestrained outrage and endless indignation (expressed by their parents as well as their peers) are the norm. Their social media discourse thrives on condemnation and criticism. Far from showing respect for authority, establishment or the status quo, their feeds – and maybe increasingly their instincts – are predicated on attacking it.

This can be energising – political campaigning and advocacy amongst young people is at its highest level for a generation. And there’s a scepticism that can be healthy. But when all experts are doubted, when parents side time and again with their offspring rather than their teachers, the balance has tipped too far.

As a society, do we want complaints and outrage to be the norm? It’s hardly an inspiring way to live. But it is a call to arms for us to champion with our students the fights that really matter. All of us who work in schools have the opportunity to present different messages. To give children a faith – regardless of the religious context. It is our job, surely, in the face of all this noise, to remind children to form their own opinions, fight their own battles and risk making their own mistakes along the way.

Parents and teachers who scaffold answers, ease their students to a better grade and remove all obstacles from their children’s lives miss the point. The moment, after many failed attempts, when something suddenly falls into place and makes sense is richly satisfying and still one of the greatest pleasures that life can afford.

Hard work is, in and of itself, not only a worthwhile endeavour but an important and life-enhancing skill. The world is big and full of opportunity – and flaws – and embracing all these independently will help to breed success and possibility when school is done and the big wide world awaits.

Jane Lunnon is the headteacher of Wimbledon High School, GDST

Jane is speaking at this year's Bryanston Education Summit, which takes place on Wednesday 5 June. For more information, click here.