#WhatWeDidOnOurHoliday is movie perfection. Well done @BBCFilms

It’s tempting to say What We Did On Our Holiday is the perfect movie. In truth, though, it’s only perfect for certain segments of society.

If you’re a parent or a grandparent, if you’ve ever fallen in love or had your heart broken, if you’ve been married, or married and divorced, if you have complicated relationships with siblings, or if someone close to you has died, well then this movie is for you.

If not, you’ve led a spectacularly uninteresting life and this story is not for you.

Released last year in the U.K. and this summer in North America, What We Did On Our Holiday centres on the relationship of three young children and their cancer-stricken grandfather, played by Billy Connolly. Yes, that Billy Connolly, doing what Billy Connolly always does.

He is exactly the kind of wise old Scottish smartass that you’d expect. But in this setting, it’s perfect. He represents what grandfathers often are to their young grandchildren: fun-loving, rule-breaking founts of joy and irreverence. When he tells the three youngsters that he’s a descendent of Vikings and wants a proper Viking funeral, the kids soak up every word, including the fictional bits about how Vikings memorialized their dead.

When the kids follow his wishes, the reaction of their parents is, by turns, predictable, depressing and hilarious. The chaos that ensues shreds the veneer all the adults have been fighting so hard to maintain, a veneer covering infidelity, divorce, depression and the common neuroses every family faces at various times.

It falls to the children to teach the adults around them what really matters – lessons learned from their grandfather. That they miss the nuances of many situations and forge ahead with innocent determination only concentrates the point that much of what we spend our time worrying about is meaningless.

The children carry the movie and deliver most of its best lines. Let’s face it, little kids with British accents delivering non-sequiturs and unfiltered observations are very funny. Their parents, played by Rosamund Pike and David Tennant, represent flawed parents everywhere.

With potential clichés lurking at every turn, the film steers a refreshing course, dabbling, but never drowning, in sentimentality, and wrapping up in an uplifting but realistic conclusion, rather than a saccharine happy ending.