"Sharp drops from a high altitude to a small one, minute overload, from which sometimes it darkens in the eyes - all this is easily tolerated by a physically hardened person. Sometimes in battle, performing a cascade of figures, you lose consciousness for a moment. You will come to your senses, now you are included in the combat situation and again you act at any height, at any speed, in any position."
January 1, 1970
https://en.wikiquote.org/wiki/Ivan_Kozhedub