I am sitting on a bench at the playground with my best friend Tim. Tim is the same age as me. Today we don’t feel like swinging. And we don’t feel like playing football either.

Next to me lies a picture book that my dad gave me as a present.
A book about the forest.

I open it.
Big green pictures. Trees with so many leaves that you can hardly count them.

Tim leans closer.
“How many leaves do you think a tree like that had?” he asks.

I shrug. We think about it.
Because today, forests look very different from the ones in the book.

Then I remember a story.
A story my dad once told me.
And now I tell it to Tim.

“Many, many years ago,” I say,
“the trees didn’t feel like growing new leaves in spring anymore.”

Tim frowns.
“Why not?” he asks.

“My dad said,” I explain,
“that the air and the water had become too bad.”

Tim doesn’t say anything.
He just asks me to turn the page.

On the next page it says that every tree had its own smell.
Like fresh air.
Like joy of living.

Tim and I look at each other.

“What do our trees smell like?” I ask.

Tim sniffs the air.
“No idea,” he says. “Our trees don’t smell at all.”

I nod.
“That’s a pity,” I say quietly. “I wish our trees could smell again.”

We turn the page.

Now we see pictures of trees with red, round fruits.
“Cool,” says Tim. “That must be fruit.”

“Looks tasty,” he adds after a moment.
“I wonder what it tastes like.”

I think for a bit.
“No idea,” I say. “Fruit doesn’t grow on trees anymore.”

Tim grins.
“I’d like to travel back in time,” he says,
“and get two apples for us.”

He asks me to turn the page again.

Now things get exciting.
The pictures show how a small brown thing turns into a big tree.

“That’s called a seed,” I read.

“If I understand it right,” I say to Tim,
“the tree comes out of the seed. First one single leaf, and then it keeps growing.”

“Like a magic tree,” Tim says.

The text says that it takes a hundred years for a tree to be fully grown.

Tim points to the last picture.
“That tree is older than my grandpa,” he says.
“And it’s so green.”

We turn the page again.

Now it gets difficult.

There are drawings explaining that the leaves and the tree can make air out of water and air.
I don’t really understand it.

“Can you explain that to me?” I ask Tim.

He shrugs.
“Maybe there was some kind of air factory inside the tree,” he says.

Then he points to the gray building next to the playground.
The fresh‑air factory.

We turn the page again.

Now there are pictures of trees without leaves.
That was the time when the trees didn’t feel like trying anymore.

On the last pages we see people building trees.
Trees like the ones at our playground.

They all look the same.
They don’t smell.
They aren’t green.

“Our trees are built by people,” I say.

Tim nods.

We close the book.

It’s quiet for a moment.

Then I ask,
“Do you want to play football?”

Tim stands up.
“Yeah,” he says.

And we run off.