In an experiment, a scientist placed a number of fleas in a glass jar. They quickly jumped out. He then put the fleas back into the jar and placed a glass lid on top of the jar. When the fleas jumped, they hit the glass lid and fell back into the jar. After a while, the fleas started jumping slightly below the glass lid to avoid hitting it.
After a while, the scientist removed the glass lid. But the fleas continued jumping below the height of the glass lid. They had learned to stop themselves from jumping beyond the height of the lid.
Now, no matter whether the lid is there or not the fleas will stay in the jar forever. When the fleas get babies, their babies too will copy their behavior and will not jump high either.
Just like the fleas, we too set limits to what we can achieve. We don’t jump as high as we can. Think of those who have jumped high and achieved great things! Let us jump as high as we can and succeed!