The person you are is the person you chose to become. Every choice in your life changes how you really want to be. Beware of your actions and think deep before every step you're making, or you'll end up not knowing who you've become or how to get your old self back!
The chase of excellence has been nowadays highly emphasized by people who think and know that they are capable of more. They do not stop at good. They do not stop even at best. They seek for the highest achievable result and they would still want more. How's 10 out of 10 for you?