The number of neurons is impressive but limited. And nobody cannot control every possible thing and situation in the world.

Sometimes people are asking why brain research is so difficult? The answer to that question is simple. We are brains ourselves. When we are researching brains, we are researching ourselves. The number of neurons is impressive but limited. And that means the data mass that is stored in those neurons is limited. If there is a limited number of neurons there are limited numbers of data storing units. And that means there are limits in knowledge and skills that people have. 

Brains are things that are the most dominating in our life. Because without brains is no mind and humanity. But what comes first mind or brain? There are billions of neurons and trillions of connections in the human brain, and those connections and neurons are creating the electrochemical vortex called the mind. 

The structure of neurons and axons is useless without that electrochemical vortex, which is like the software of computers. But which comes first mind or brains? There is always the first neuron in the human brain. And another thing is that there are skills and other kinds of behavior that are transmitted in the DNA. Those things are afraid of snakes and spiders, which mission is to keep the human alive. 

But which skills are learned and which are descending? Afraid of something means the need to avoid contact with that thing. So fear is the sign, that something is dangerous. Those descending skills are the thing, that is making the base for the learning. Learning things is otherwise saying growing the number of skills.

When brains are learning new skills, they are storing that thing in the database if that thing is useful. If skill is useless the neurons are removing the axons or connections from that database. That removal of connection is forgetting. 

The reason why we cannot remember everything is that forgetting keeps the number of connections limited. One neuron can have hundreds of connections, but the fact is that a large number of connections is slowing the neuron. The fact is that nobody can know everything. The number of neurons, databases, and connections is limited. And that means that something is always outside the skills that are stored in databases. 

That cell must always check all its connections when it's looking for data. And forgetting things keeps the working memory and number of databases in the human brains compact. If we cannot forget things, the databases in our brains will grow. And a large number of databases is making brains slower. 

When we are thinking of databases as papers, there are instructions for the actions. We can compile situations where the creature has only one skill to the creature that has multiple skills. If the creature has only one paper in use, that means the reaction is fast. But it doesn't fit all situations. If the creature has multiple skills. There is needed lots of paper. And the creature must check all papers for selecting the right skill for the right place. This is why artificial intelligence that has versatile skills is slow if we compare it with limited artificial intelligence. 

But the limited artificial intelligence has a limited operational sector.  So if we are transforming that model to humans, we must realize that if a person knows only one skill, that makes the person fast. But also the one skill is not suitable for all situations. And those kinds of persons who have limited skill area require lots of assistance. If they want to make the actions that are outside the skill, that they have. 

If we have only one skill, there is no problem selecting those skills what to do. The reaction of that kind of person or creature can be extremely fast because there is only one database to choose from the structure. If the person has many skills. That means that the brain must search the databases, that are involving the actions. And if there are many databases that process is slowing the action.