It is difficult enough to master any task. Many that claim mastery can only perform under ideal circumstances with the right set up. It is often the case however, that we are forced to perform in less than ideal circumstances and under less than ideal conditions. In less than perfect conditions we can assume that our performance will wane, but training FOR this, assures us that we will be better prepared to handle the unknown. And we get closer to mastery.
Check out the Wed. Crew testing the limits of their mastery.