"Certain men might have been something if they had not thought themselves so. A consciously great man is an evidently little one." -C.H Spurgeon
A great man is a humble one, If we view ourselves as great and think we should be treated as so, then we are not great and we will always be angry that we are not being treated as we think we deserve. Mark 10:43 says that, "Whoever would be great among you must be your servant." We must be servants, then we will be great in God's kingdom.
Matthew 20:27-28, "And whoever would be first among you must be your slave, even as the son of man came not to be served but to serve, and to give his life as a ransom for many."
Even the greatest person ever came to serve, and if we want to be great we must follow his example.