Why did this bit of the world, Europe, end up being the bit that did all the colonising, conquering and exploiting? I think that there is an argument to be made that all these little kingdoms at each others throats, no more than a week or twos ride from each other probably did force people to 'think different', but there other things that came into play.
It didn't ... "end up" is relative - loads of civilisations have done it. Most famously the Romans, but here's the full list:
http://en.wikipedia.org/wiki/List_of_largest_empires
We're all at it - all of the time... Europes time is on the wane though.