"When you are flying, everything is all right or it is not all right. If it is all right there is no need to worry. If it is not all right one of two things will happen. Either you will crash or you will not crash. If you do not crash there is no need to worry. If you do crash one of two things is certain. Either you will be injured or you will not be injured. If you are not injured there is no need to worry. If you are injured one of two things is certain. Either you will recover or you will not recover. If you recover there is no need to worry. If you don't recover you can't worry."
From W.E.Johns, Spitfire Parade (1941)