It is most likely impossible for a single person to know everything. No matter what the capacity of a person's brain is, it would not be able to learn and recall this huge amount of information. Therefore, for biological reasons, there are limits to what humans can know.
However, this does not mean that we should deliberately limit what a person can know. There should not be any limits to the information that a person can access, because by making knowledge available to all, our society and our whole world at large will benefit.
It should not be limits to what humans now. I think this because, if you have limits you will never learn another things. Also, our capacity of remember things will be not that good. Because if you don't learn anything you will start forgetting things. Finally, I think that there shouldn't be limits to what humans can know.
The connotation is the extra feeling that a word carries. Using words with different connotations can really change the meaning of a sentence and the tone, which means the attitude of the speaker.
