Years after those childhood games and imaginings, he found himself in London with his theatre-making partner, Hannah Smith, and, feeling a bit homesick, began to craft a story rooted in New Zealand folklore.
It became The Road That Wasn't There, a dark fairy-tale play set in a more mythical Central Otago than the one we know.
Here, a lost moa roams the foothills; faeries drink moonshine and a young woman strays from the beaten track to find herself in a paper world. It seems a land of possibility but she soon discovers that things that happen in the fictional world can have frighteningly real consequences.
The second show made by McCubbin Howell and Smith's Trick of the Light theatre company, it premiered at the Edinburgh Fringe Festival in 2012 then toured New Zealand the following year. Five years after its debut, they're bringing The Road That Wasn't There back - more refined and with changes here and there - to start another international journey.
That involves returning to Edinburgh but before they leave, accompanied by fellow cast members Paul Waggott and Elle Wootton, they'll perform in Auckland and Wellington. The Road That Wasn't There fits well within the Southern Gothic style of theatre that has won Trick of the Light fans around the world.
Smith describes it as taking the everyday and transforming it into something a little bit magical. She says they're interested in the magical and mysterious and play with shadows, puppetry, live music, darkness and light.
If they have to liken The Road That Wasn't There to books younger audiences - those 7 and above - might know, they'd pick one by Margaret Mahy or Neil Gaiman. It is, they say, a challenging genre to get right in theatre.
"It's certainly a genre which exists more in literature or film than theatre," says McCubbin Howell, "but there's an intensity and immediacy in a theatre where everyone is together, in the dark, and not on iPads or screens."
As Smith points out, children don't necessarily have to be outside to have an adventure.
"You can stay indoors and pretend to ride a magic carpet or pick up a glass and start to make up a story about the ocean in it."
They hesitate to call their theatre family shows. McCubbin Howell says that's because their shows will appeal to adventurous adults and intrepid older kids alike.
Does it bother them that they have to leave home so often to work?
Not at all. McCubbin Howell says while New Zealand is a beautiful place to live, and fuels their creativity, we have a small population and working overseas is simply part and parcel of their lives.
Lowdown
What: The Road That Wasn't There
Where & when: Herald Theatre, Aotea Centre; July 11-15