What is the nature of power? Physical strength, psychological intimidation, vast knowledge, uncanny ability, they all represent the ability to manipulate a medium (the physical world or peoples minds) to your will.
Given this, is there a reason to seek power if not for a purpose? Power for power's sake is rather useless, since what would you do with the ability of manipulation when you don't have something you wish to bring about?
Yes, having power can be quite a heady rush, but you can get the same rush through accomplishing something important, the endorphins released by exercise, or solving a tricky intellectual problem.
Twould make more sense to seek a purpose first, before seeking power. Just saying...