Do you want to stay humble for the rest of your life, then you might want to take some time to read this post, it may somehow remind us of how we must be.
Nobody knows everything except for our almighty God. One can not boast of his skills or knowledge about knowing something or everything; for instance a medical doctor should not disparage a mechanic nor a weaver. Technically, each is a master in his own field. The doctor and the mechanic is not knowledgeable of the weaver's thing, vice versa. That is the most literal explanation we can cite but it is TRUE, indeed!