There are books we read as children. Then some books wait patiently for us to become adults before revealing the joke. Calvin and Hobbes is one of them.

When I first encountered Calvin, I thought he was simply a wonderfully naughty little boy with an unusually philosophical tiger for a friend. He had grand adventures, invented machines out of cardboard boxes, argued with adults, escaped homework whenever possible and generally behaved as though the world had been created specifically for his entertainment. I loved him immediately.

Years later, I realised something rather alarming. I had grown up. And I now understood Calvin’s parents. This is one of the less advertised stages of adulthood.

As children, we look at Calvin and think, What a brilliant fellow.

As parents, we look at him and think, Please don’t give my child any ideas.

And somewhere between the two lies the truth about childhood.

Bill Watterson’s Calvin and Hobbes ran from 1985 to 1995, following the adventures of six-year-old Calvin and Hobbes, his stuffed tiger who, depending on whose eyes we see through, is either a toy or very much alive. The strip mixed mischief, imagination and philosophical curiosity in a way that allowed children to laugh at the adventures while adults noticed some of the deeper jokes.

For those of us who grew up in Madras, there was something instantly familiar about Calvin’s world. We may not have had his cardboard time machine. We had something better. A terrace.

A terrace in Madras could become practically anything. A cricket ground. A battlefield. A railway station. A secret headquarters. A place to dry clothes while simultaneously conducting an international cricket match around them.

And if the ball landed somewhere it shouldn’t, the expedition began. “Don’t climb there!” was usually heard from a distance. Naturally, this was not interpreted as an instruction. It was interpreted as background sound.

Madras childhood had its own special form of entertainment. There were bicycles, marbles, cricket bats, comic books, cousins arriving for the holidays and afternoons that seemed to last forever.

There were no carefully designed activity schedules. Nobody needed to “keep the child engaged”. The child was perfectly capable of engaging himself. Usually with something the adults had specifically asked him not to touch!

A cardboard carton could become a fort. A bedsheet could become a tent. A stick could become a sword. A neighbourhood wall could become a perfectly legitimate cricket boundary, provided nobody asked the owner.

And boredom? Boredom was not considered a developmental concern. It was considered an opportunity. You were simply expected to go and find something to do.

Calvin would have approved. Perhaps this is why his imagination feels so familiar. He takes the ordinary and turns it into something enormous. A box becomes a spaceship. A school day becomes an epic struggle. A walk outside becomes an expedition.

A Madras child needed no lessons in this. We had already mastered the art.

A visit to Marina Beach, for instance, was never simply a visit to Marina Beach. There was sand. There were waves. There were snacks. There was running. There was the solemn parental instruction not to go too far into the water.

And there was the child calculating, with impressive scientific accuracy, exactly how far “not too far” might actually be.

Parents, meanwhile, developed a remarkable vocabulary: “Come here.” “Don’t run.” “Careful.” “Leave that.” “Enough.” “Did you hear me?”

The last question was largely ceremonial. The child had heard everything. The child had simply decided to proceed differently.

Calvin’s parents understand this. They are among the great unsung heroes of the comic strip. They are not villains. They are not perfect. They are simply two adults attempting to raise a six-year-old whose imagination appears to have no closing hours.

For Chennai parents, this is deeply reassuring.

Because we have all encountered Calvin. Perhaps not in exactly the same form. But certainly in the child who cannot find the school notebook despite it being on the table.

The child who remembers at 8.30 p.m. that tomorrow is “special dress day”.

The child who announces that a project is due the next morning.

The child who needs chart paper, glue, coloured paper and one very specific shade of glitter immediately.

And when the parent asks, “When did you know about this?” “Last week,” comes the innocent answer!

There are moments when parenting requires the patience of a saint, the organisational skills of a railway station master and the reflexes of a goalkeeper.

And then the child smiles. And somehow, the whole thing is forgiven. That is another thing Calvin and Hobbes understands beautifully.

Children can be exhausting without being unlovable. They can be unreasonable without being bad. They can drive adults completely mad and still make them laugh five minutes later.

Perhaps that is why the strip remains so beloved. It does not present childhood as a perfectly behaved little paradise. It ­presents childhood as it actually is – noisy, imaginative, selfish, curious, dramatic, funny and occasionally covered in something that nobody can identify.

And then there is Hobbes. Every child deserves a Hobbes. Someone who listens to the wild ideas. Someone who enters the game. Someone who understands that a cardboard box may actually be a spaceship and that an ordinary afternoon can become an expedition to another planet.

Most of us had a Hobbes of some kind. Perhaps it was a favourite toy. Perhaps a school friend. Perhaps a cousin who was always ready for the next adventure.

Or perhaps it was simply our own imagination. For many of us who grew up in Madras, childhood had plenty of room for that imagination.

Perhaps the greatest difference between childhood then and childhood now is not that children have changed.

Children are still children. They still want to play. They still invent worlds. They still ask inconvenient questions. They still have an extraordinary ability to discover the one object in the house they have been specifically told not to touch.

What has changed is the world around them.

Our childhood had more empty spaces. And empty spaces were wonderful things. They gave imagination somewhere to go.

Today, children have schedules, classes, screens, activities and wonderfully organised weekends. And yet give them a cardboard box, a blanket and half an hour of freedom, and Calvin will probably return.

That may be the enduring magic of Calvin and Hobbes.

It reminds adults that childhood is not merely a stage we pass through. It is a place we continue to carry.

Sometimes it returns when we see a child turning a chair into a spaceship. Sometimes it returns when we hear an old joke. Sometimes it returns when we find an old comic book. And sometimes it returns when our own child does something completely ridiculous and we suddenly hear ourselves laughing before we can say, “Stop!”

That is when we realise something. We did not leave childhood behind. We merely changed our address.

Once, we were the ones being called home. Now, we are the ones doing the calling.

Once, we were Calvin. Now, somewhat alarmingly, we are Calvin’s parents.

And somewhere between shouting “Don’t climb that!” and “Come and eat your dinner!” – we discover that we have become the adults we once thought were hopelessly unreasonable.

Perhaps that is the real trouble with being six. You eventually grow up.

But thankfully, a small part of you refuses to. It keeps the cardboard box. It remembers the terrace. It misses the endless summer afternoons. It laughs at Hobbes. And every once in a while, when nobody is looking, it still imagines that the box is a spaceship.

Which is probably why Calvin and Hobbes never really left us. They simply waited.

For us to grow up. And understand the joke.