As we saw earlier, when a difficulty comes to mind, the brain’s habitual reaction is to treat it as a real enemy, so it tends to shut down its creative “approach” systems. For some difficulties, it might be necessary to shut down playfulness, but when you are remembering the past or anticipating the future, the difficulty is playing out in our heads and not for real, so this is unnecessary. In fact, it ends up locking things down and blocking creativity: we either feel trapped and the body slumps into submission or the body gears up to fight or flee. Prof Mark Williams