I try to keep in my mind the simple question: Am I trying to do good or make myself look good? Too many of our responsibilities get added to our plate when we are trying to please people, impress people, prove ourselves, acquire power, increase our prestige. All those motivations are about looking good more than doing good.
I think that when we know that we actually do live in uncertainty, then we ought to admit it; it is of great value to realize that we do not know the answers to different questions. This attitude of mind - this attitude of uncertainty - is vital to the scientist, and it is this attitude of mind which the student must first acquire.