Try to see yourself as you truly are and try to adopt what is meritorious in the work of others. As a [martial artist] you will of course often watch others practice. When you do and you see strong points in the performance of others, try to incorporate them into your own technique. At the same time, if the trainee you are watching seems to be doing less than his best, ask yourself whether you too may not be failing [in that same area]. Each of us has good qualities and bad; the wise man seeks to emulate the good he precieves in others and avoid the bad.

- Gichin Funakoshi, founder of Shotokan Karate,

There is a lot of wisdom in this quote. One part in particular has been enlightening  for me – when you see a fighter make a mistake it is easy to criticize instead of checking yourself to see if you too have the same malady.  I’ve been told that the faults we possess are easy to see when they are exhibited in others, but elusive in ourselves.

Know yourself. See what is being proven effective. Evolve.