Not sure what general opinion is "out there" regarding the state of mind you need to be in to sail at and past peak levels. I read a great book in my younger Optimist days The Winning Mind and have re-read it several times since.
Its failrly light weight with some good practical activities you can do on the water to improve your general performance. A lot of it is about being able to sail 100% subconsciously and naturally so you're mind can focus out of the boat on tactics, elements and the competition.
I particularly like (and have used succesfully) 2 key approaches, the first is mentally sailing round the course, doing boat handling in the mind, tacking on shifts and reacting to incidents - its amazing what scenarios your active brain can think up! When you come to an area that doesn't go well i.e. a bad gybe, you can then replay it in your mind, see where the problem is, fix it, try again until mentally you sail a polished race - its then a lot easier to fix these things on the water... honestly.
The other great exercise, which is even easier to do when your sailing in a 2-man boat, is for the helm to close his eyes and sail by the "feel" of the boat, this is the best way 2 become really in tune with how the boat feels when you are pinching, hitting waves or even sitting in the wrong position in the boat. The book explains it a lot better.
Search for the "Winning Mind" in my Amazon section and you will find the sailing one (above) and other books on this interesting subject.
Email me or leave your comments as to what you think to this subject...