When Peter Fortune was ten years old grown-up people sometimes used to tell him he was a “difficult” child. He never understood what they meant. He didn’t feel difficult at all. He didn’t throw milk bottles at the garden wall, or tip tomato ketchup over his head and pretend it was blood, or slash at his granny’s ankle with his sword, though he occasionally thought of these things. Apart from all vegetables except potatoes, and fish, eggs and cheese, there was nothing he would not eat. He wasn’t noisier or dirtier or more stupid than anyone he knew. His name was easy to say and spell. His face, which was pale and freckled , was easy enough to remember. He went to school every day like all other children and never made that much fuss about it. He was only as horrid to his sister as she was to him. Policemen never came knocking at the front door wanting to arrest him. Doctors in white coats never offered to take him away to the madhouse. As far as Peter was concerned, he was really quite easy. What was difficult about him?

It was not until he had been a grown-up himself for many years that Peter finally understood. They thought he was difficult because he was so silent. That seemed to bother people. The other problem was he liked being by himself. Not all the time, of course. Not even every day. But most days he liked to go off somewhere for an hour to his bedroom, or the park. He liked to be alone and think his thoughts.

Now, grown-ups like to think they know what’s going on inside a ten-year-old’s head. And it’s impossible to know what someone is thinking if they keep quiet about it. People would see Peter lying on his back on a summer’s afternoon, chewing a piece of grass and staring at the sky. “Peter, Peter! What are you thinking about?” they would call to him. And Peter would sit up with a start . “Oh, nothing. Nothing at all.” Grown-ups knew that something was going on inside that head, but they couldn’t hear it or see it or feel it. They couldn’t tell Peter to stop it, because they did not know what it was he was doing in there. He could have been setting his school on fire or feeding his sister to an alligator and escaping in a hot air balloon, but all they saw was a boy staring at the blue sky without blinking, a boy who did not hear you when you called his name.

As for being on his own, grown-ups didn’t much like that either. They don’t even like other grown-ups being on their own. When you join in, people can see what you’re up to . You’re up to what they’re up to. You have to join in, or you’ll spoil it for everyone else. Peter had different ideas. In fact, he thought, if people spent less time joining in and making others join in, and spent a little time each day alone remembering who they were or who they might be, then the world would be a happier place and wars might never happen...

The trouble with being a daydreamer who doesn’t say much is that the teachers at school, especially the ones who don’t know you very well, are likely to think you are rather stupid. Or, if not stupid, then dull. No one can see the amazing things that are going on in your head. A teacher who saw Peter staring out the window or at a blank sheet of paper on his desk might think that he was bored, or stuck for an answer. But the truth was quite different.

For example, one morning the children in Peter’s class were set a maths test. They had to add up some very large numbers, and they had twenty minutes to do it. Almost as soon as he had started on the first sum, which involved adding three million five hundred thousand, two hundred and ninety-five to another number almost as large, Peter found himself thinking about the largest number in the world. He had read the week before about a number with the wonderful name of googol . A googol was ten multiplied by ten a hundred times. Ten with a hundred noughts on the end. And there was an even better word, a real beauty—a googolplex . A googolplex was ten multiplied by ten a googol number of times. What a number!

Peter let his mind wander off into the fantastic size of it. The noughts trailed into space like bubbles. His father had told him that astronomers had worked out that the total number of atoms in all the millions of stars they could see through their giant telescopes was ten with ninety-eight noughts on the end. All the atoms in the world did not even add up to one single googol... If you asked someone for a googol of chocolate-covered toffees, there wouldn’t be nearly enough atoms in the universe to make them.

Peter propped his head on his hand and sighed. At that very moment the teacher clapped her hands. Twenty minutes were up. All Peter had done was write out the first number of the first sum. Everyone else had finished.