Eisenhower famously composed a statement, never released, announcing that the invasion had failed, and taking responsibility for the decision to go.Dale Carnegie, author famously of How to Win Friends and Influence People, also wrote How to Stop Worrying and Start Living. In that book, he recommended Eisenhower's procedure. Which amounted to figuring out what was the worst thing that could happen, and accept that it was going to happen. Because when you just worry, you act like the worst is unbearable. Being realistic about what was the worst result is the best way to control worry. So goes the theory, anyway.
I would disagree with the notion that someone should ‘accept’ that the worst WILL happen.
In a position like Eisenhower’s, I can see preparing a statement; he had duties on the physical plane - and nobody really ever *knows* how things will go.
But ‘accepting’ the negative, in one’s personal mind, is opening the door to it.
Within ourselves, for the best chance at the best outcome, we have to accept and expect only the Best.
‘Imagination is a great Nation’, as my old Granny always said :-)