I read a book called ‘Good to Great by Jim Collins once. He spoke about the Stockdale principle in relation to long term p.o.w. Prison camps and how optimists were not the ones who survived. Realists did.
The reason was that the optimists kept thinking they would be free soon but they never faced the reality that they may never get out. As a result they were constantly disappointed and died in their cells many . But the realists dealt in facts. The reality of their current circumstances. They were the ones to survive.