Mmkay, you've gained complete control of gravity as a whole. Now, you must spend your entire life regulating gravity throughout the universe. If you screw up, the universe may implode or something. I guess you could use that as leverage to make yourself universal dictator, but you still have to spend your entire life concentrating on keeping the universal balance so your mind is too preoccupied for dictatorship to even be worth it.
I wish my hair was always nice and well-managed.