The first barrier to study is not having the real thing there that you are studying about. The real things or the object that you study are called “mass.”
If you were studying about cars, you could get the mass of a car by going to a real car and looking at it and touching it.
If you were reading about animals, you could get the mass of animals by going to a zoo or a farm.
Studying about something without having the mass of what you are studying can give you trouble. It can make you feel different ways.
It can make you feel squashed.
It can make you feel bent,
sort of spinny,
sort of lifeless,
You can wind up with your stomach feeling funny.
You may get headaches.
You will feel dizzy from time to time.
and very often your eyes will hurt.
The way to stop this from happening is to get the mass of what you are studying.
Sometimes you cannot get the real object you are studying about.
When this happens, pictures help. Movies would help too.
But reading books or listening to someone talk does not give you mass.
They do not take the place of what you are studying about.