If you feel you're not getting any better, like you've hit a plateau, then you need to make new demand on yourself.

I read a story by Dale Carnegie (author of How to Win Friends and Influence People) about when he once met one of the world's top bodybuilders. Dale inquisitively asked the guy how, exactly, he was able to get such huge muscles. The bodybuilder told him, in no uncertain terms, that every day he went in the gym and forced his muscles to get bigger by progressively lifting heavier and heavier weights. "These muscles expand by demand!" he explained. The tenth of a 10-rep set is the hardest. But all the growth, Tony Robbins says, comes from rep #11.

It's the same for any of us, in whatever we do: We must decide there is a higher level we can reach, and make a demand on ourselves to reach it. A new standard.