Richard Feynman, populist physicist, Nobel Prize winner, and contributor to the atomic bomb, used to be fond of telling a story about helping out a friend in the psychology department at the Massachusetts Institute Of Technology. His friend was conducting behavioral experiments with rats. She had set up a corridor with several doors on each side. On one side, the rats would be let into the corridor. On the other side, there would be food behind one of the doors. She wished to see if the rats could be trained to go in the third door to the right every time, with or without the reward of food and regardless of the door at which they began.
The rats would immediately go to the door where they had found food the time before. Which door they had started from or how many doors away it was appeared to be meaningless.
Making the realization that there had to be some clue instructing the rats toward the door concealing the food, she decided to meticulously paint each of the doors to be exactly alike so there would be no visual cues. Still the rats found the food immediately.
Assuming they could smell the food, she used chemicals to disguise the food's odor. It made no difference. The rats continued to go directly to the door with the food.
She covered the ceiling with sheets in an effort to eliminate the lights as what she believed to be obvious navigational markers. Yet the rats promptly honed in on the food once again.
While his friend was confoundedly wringing her mind, Feynman began to crawl around the hallway trying to emulate the rats' experiences. What he found was that the floor made different sounds in different places. Each door had unique hollow or hard or noisy spots around it. He suggested to his friend that the rats were relying on sound to seek out the food.
The two covered the corridor with sand and then released the rats again. Sure enough, the rats were confused and could not find the food. Eventually, the rats were able to be trained to go toward the third door on the right every time.
As soon as the young scientists stopped making assumptions of what the rats were experiencing and began looking at the problem from the rats' point of view, everything was illuminated.