As usual, the answer probably lies somewhere in the middle. There are things you can control, and there are things that you can't. Improve the things you can, and don't feel bad for the things you can't.
Exactly -- I think it's important to continually act in a way consistent with improving outcomes. This doesn't mean you will always get the outcome you want, but much like luck favors the prepared mind, continual, continuous, consistent action towards higher goals does eventually cause results.