> took thousands of years to accept brain as the seat of thought because “heart beat faster when excited, means heart is source of excitement”

So what you are saying is that beings without a central nervous system cannot experience "excitement"?

or perhaps the meaning of too many words has changed, and their context. When Hippocrates claimed that the brain was an organ to cool the blood, perhaps he meant that we use our thought to temper our emotions, i.e. what he said agrees with our modern understanding.

However, many people read Hippocrates and laugh at him, because they think he meant the brain was some kind of radiator.

Maybe because we stopped talking about "excitable" people as being "hot-blooded"