Being the greatest is a journey, not a destination and the only people who think they've arrived at the destination are either fools, or the delusional.
I think the questioner may have done a great job for someone and then let his ego get the better of him to thinking he's probably the greatest and so to test that theory out posed his questions to see if anyone else measured up.
Anyone who knows anything about this business knows you're only as good as you're last job - fullstop!
Simon