Fitness is a curve. You can be Lance Armstrong, or you can be really out of shape at the opposite end. People enter the curve wherever they are and then they can move up the curve, by better nutrition and better exercise.
I'm a better coach now than when I joined Celtic. The longer you stay in any job, the better you become. If you lose your drive, your enthusiasm, your imagination, that experience is no good.
I like to be able to control which players I'm working with. Because it doesn't matter how good a coach you are if the guys you're working with think they already know it all. You need a response, you need to feel they're trying. I want players who are always striving to improve.
It took me 35 years of being involved at a decent level of football to become manager at a great club like Celtic.