What is the message of the story?

Kabir's project for the science fair was a small model that produced electricity from the motion of water. For two weeks he worked on it every evening, and on the night before the fair it lit a tiny bulb perfectly.

On the day, in front of the judges, it did nothing at all.

Kabir checked the wires and the little wheel. He poured the water again. Nothing. Across the hall, his rival, Dev, was showing a robotic arm that picked up a pencil, and a crowd had gathered round him.

One of the judges, a retired engineer with thick glasses, waited patiently. "What do you think has gone wrong?" she asked.

Kabir's first wish was to say that it had worked yesterday, which was true, and to blame the water in the school tap. Instead he took a breath and thought aloud. Perhaps a wire had come loose on the bus. Perhaps the wheel was rubbing against the box. He opened the box. The wheel was rubbing against the box.

There was not time to mend it properly, so he explained to the judge exactly what should have happened, and why it had not, and how he would fix it.

Dev won the first prize. Kabir won nothing. But as the judges left, the engineer stopped at his table. "I have seen many machines work," she said. "I have seen very few students find out why one didn't. Keep that habit."