Here's a question I've been pondering lately. Whatever activity you pursue, which involves improvement in some way, is there a point when you say "I can do no better"? I've often heard it said that you never really stop learning/improving, particularly when this applies to playing a musical instrument. It's true that as you progress in anything, then there comes a point where further improvements becoming difficult to achieve. But you could argue that if you reach a plateau, then doing something different may yield improvements. Take running: Even if I trained my backside off, I couldn't achieve what Mo Farah does. I simply don't have the genetics. I have an upper potential, but how do I know when I've reached that? I'd like to think I can still improve, and you should always think positive, but at what point do you say, I'm as good as I can be?