Successful person develops ego that doesn’t allow him to achieve the deserving greatness ? Why he does that?

A successful person doesn't let vanity get in his/her way.They are never finished.I mean the more they learn,the more thet realize there is to learn.Should they lie back on their laurels,than the thirst would be quenched and there would be no motivation to keep driving them on.(you see that up above?Not thet but they).I have never known a "successful" person that had a satisfied ego.In fact as I hinted at in an earlier question,I am not even sure what "success" is.Just keep those questions coming Gentleman as they are very stimulating to me.I only wish I had the adequate time to answer them completely as I wish...