What is the meaning of the line "don't look too good, not talk too wise"?

In this line, "And yet don’t look too good, nor talk too wise...", Kipling is cautioning his son that the appearance of goodness isn't enough...... humility (humbleness) is required as well.

It means that you should not be very good that people take advantage of you. Nor should you behave that you are the wisest.