Why does Australia say they can improve on their win against Sri Lanka on Friday?

Australia were 6/253 and dismissed SL for 125 - less than half of the Australian total yet they are still saying they can improve. They are basically saying they could have done better. How arrogant and how obsessed with winning are they? I can't understand the mentality of this Australian side in which a thrashing of this nature shows there is still room for improvement. The only need for improvement is in the area of humility.