It's a VERY dangerous thing! It is a very dangerous thing because we tend to believe that it is all we need to know about any particular subject. It is fine if we recognize that we know only a little, because then we continue asking questions and we try to integrate the increasing amounts of knowledge in any particular subject with the rest of the vast reservoir of information we have. And that is one huge reservoir indeed, for it has been said that if we learn one new thing every second, our minds would take all of three million years to be filled up to capacity!
None of us knows everything. But all of us can know what the nature of truth is. When we are presented with information or viewpoints, we all need to measure what we see and hear and feel by universal, non-negotiable principles. We all have a certain sense of what is true and what is not. Trouble with us as human beings is that we suppress what we know to be true in favour of what we desire and know to be convenient. Most of us have a preference for not rocking the boat, idling along as it does on our peacefully pristine pond. Few there are amongst us who desire venturing out into unknown waters in order to discover new things. Most of us have been too well-schooled for that! We have achieved unconscious competence in the field of swallowing, hook, line and sinker, basically everything fed to us by our exalted gurus. Few ask questions, The majority simply accept what is dished out "as is."
Are you worried that you only have "a little knowledge" in many areas of expertise? Fret not, you can always start exploring in the direction of your own inclinations and learn more about what interests you. And, yes, I suspect that even after a full lifetime, we will still be only able to know a little more. But we would have continued being hungry, being thirsty, with good appetites, and we would have continued to grow.
That, my friends, is life. And that is very good value.