Add science to the AH equation and there is no way some of the maneuvers we see here could ever have been actually preformed without knocking your head off the canopy repeatedly, sometimes with enough force to disable you, eye popping negative G's or long term blackout ending in confusion and death.
Remember that most pilots needed to have loose enough restraints to position their bodies in a way that the head could turn easily for a look behind them constantly while in a fight.