Well, it is not so much about the time you spend playing but rather the level of development you have reached!
I lost about a one million attack strong army in one battle and without putting any money in, just having my 7 cities well placed to rob the neighbors, it took me about two weeks to get those 1 million points back. And that was with not much time devoted to it (end of the school year is busy with exams...).
And believe me, I am very far from being "powerful"!
(maybe because I am not "rich"
)
