It’s remarkably easy to forget that theatre is essentially watching people pretend to be other people. A stage show is elaborate make believe, designed to suspend disbelief and play along.

This playfulness takes centre stage in director Sally Cookson’s stage adaptation of Peter Pan, which brings family fun to the National Theatre this Christmas.

There’s no pretence of realism; it’s the process and joy of pretending that build this Neverland. Nuts, bolts and costumery become a character in themselves. Old-fashioned counterweight techniques and scaffolding are used to propel Pan and his pals into the air.

The show, which premiered at the Bristol Old Vic in 2012, focuses on the imaginative spark at the heart of J.M Barrie's tale, with a cast of adults using role play and found objects to create mermaids, pirates, a very tricksy fairy and a ticking crocodile. There’s a trace of pantomime exuberance in the cross-dressing, role-swapping comedy and celebration of silliness. But the narrative feels sweetly sincere and a throbbing score of live rock music detracts from any twee-ness.

Grown ups playing children can be galling, but the cast capture the excitement of dressing up and losing yourself in a game without any cutesy caricature. There’s an infectious energy that reminds even grumpy grandparents and ultra-practical parents of the peculiar magic of childhood. Kids in the audience recognise this power for what it is: uninhibited imagination.

The Darling children are taught to fly using the traditional happy thoughts plus two strands of ‘fairy string’. Our little critic giggled at this acknowledgement of artifice, but still gasped with wonder when the actor swooped out over the audience.

Just as the we see the strings in the production, we see the cracks in Peter Pan. Though aptly impish and spritely, Paul Hilton’s Pan feels weary, too. In the shadow of the cockadoodledooing leader of the Lost Boys there’s a lonely, deluded man with commitment issues.

The issue of growing up, at the heart of the story and close to the hearts of audience members young and old, is bitter-sweet. It's an inevitability that threatens to crush the whole enchanted, uproarious imaginary stage world. Wendy outgrows her ability to fly, but she doesn't full lose the little girl who gave a kiss to a little boy at the window.

J.M. Barrie was right that ‘'All children, except one, grow up', but this delightful family show invites all ages to regress and remember the magic of childhood.

Recommended for ages 7+