Don't forget about the law of diminishing returns.

Decided on the impossible? Excellent. Then you must know what barriers you will encounter along the way. One of them, which is often unsettling (if you've ever been on a diet, remember how easy it is at first and difficult afterward) is the law of diminishing returns. The point is simple: the further you advance, the harder it is for you to get better. If suddenly it becomes harder for you than before, then you are on the right track and much closer to the goal than before. Just don't give up.