The great phisolopher Socrates is credited for having said "I know that I know nothing." What he meant by this is that anyone engaged in intellectual tasks must be aware that it does not matter how much they are knowledgeable, there will always be someone is is smater or has more to offer in the given field of enquiry.
Human beings can let their egos get in the way of learning something new or acknowledging their mistakes, if people are engaged in improving it is vital to be humble enough to accept criticism, even the harsher ones, so that others will be more willing to cooperate whenever necessary.