Answer:
The brain gets better with practice, so routine actions like walking become second nature. That is why your first time on the monkey bars is harder than your 100th time.
So how does the brain judge distance? The key for animals — like monkeys and humans — is in our eyes.
Where these different views overlap is how the brain is able to calculate the difference in distance and to judge depth.
This happens because the closer an item is to you, the greater the relative difference between the eyes will be compared with the object. The farther away an item is, the smaller the relative distance between the eyes will be. Our brain is great at remembering patterns, and it remembers the differences that each eye is seeing and correlates it with a distance. It can also find the distance by calculating the “convergence,” or how crossed your eyes become while looking at something. The more crossed your eyes become when looking at an object, the closer the object.
