I think this quote is appropriate for this thread.
"At the peak of tremendous and victorious effort, while the blood is pounding in your head, all suddenly becomes quiet within you. Everything seems clearer and whiter than ever before, as if great spotlights had been turned on. At that moment, you have the conviction that you contain all the power in the world, that you are capable of everything, that you have wings. There is no more precious moment in life than this, the white moment, and you will work very hard for years just to taste it again.” -- Yuri Vlasov, Soviet Weightlifter
I believe I have felt what he is talking about here a couple of times in each of the main sports I have done, wrestling, powerlifting, and Olympic weightlifting. I will always remember each time I felt this way. When it happens to you, you will know it, and it is at this time that your mind is truly right, and prepared for maximal effort.