Harry Potter and the Cursed Child’s record Olivier award success is wizard, but even before the show won nine gongs, following the most nominations ever for a new play, it was a winner for British theatre. And not just at the box office. With its creative team – including writer Jack Thorne, director John Tiffany and movement director Steven Hoggett – all nurtured in the subsidised sector, it’s a reminder that many of the UK’s greatest culture successes are only possible because of sustained arts funding.

We are suckers for the romantic lie that talent and success spring from nowhere fully formed. The skills that go into creating a great night at the theatre tend to be honed over time, through accumulated experience, endless arduous work, risk-taking and a willingness to collaborate.

Theatre is the great collaborative art form, not a place for inflated egos. One of the great joys of Harry Potter and the Cursed Child is that you can see that collaborative spirit on stage with every element of the acting, text, visuals, movement, sound and lighting working in service of each other. It is a generous show, and one that never forgets that it is a piece of theatre; its rough magic is what makes it even more beguiling. The soul-sucking Dementors are far more terrifying than any slick CGI effect the film versions delivered.

With a different team, even a different producer to Sonia Friedman, it might not have been the case. Cursed Child is not an exercise in cynicism but in love, and in taking real care of something that the team – including JK Rowling – know millions feel passionately about. The fact it is a new story, not a page-to-stage adaptation of one of the extant seven novels, is crucial. It’s a win-win situation. Not just for Potterheads who would flock anyway, but because this story – about teenage misfits, emotionally inadequate parenting, and not living up to family expectations – has a universal appeal. This is a family show that genuinely offers something for everyone in the family, and that’s why it will likely outrun The Mousetrap.

But the reason why Cursed Child is a real winner for theatre is that it draws an audience, many of whom are going to the theatre for the first time, and then doesn’t disappoint them. It gives them an experience that exceeds their expectations and genuinely brings joy – which is a far rarer thing in theatre than we like to admit.

British theatre has a slight problem around access: it desperately wants younger, more diverse audiences and first-time theatregoers. Yet when it gets them through the door it gets pretty shirty if they are bored or aren’t familiar with all the rules that evolved back in the Edwardian period. What’s important is that, in every case, an engaged and attentive audience is a delighted audience.

The Harry Potter and the Cursed Child audience is just that, and because they have such a wonderful time, maybe they will be back – not just for a second helping of Potter, but for other theatre shows too.