When you are under stress, you tend to remember only the bad things that have happened to you and find it difficult to recall the good. A similar thing happens when you think about the future: stress makes you think that disaster is just around the corner, and when you feel unhappy or a creeping sense of hopelessness, you find it almost impossible to look to the future with optimism. By the time these feelings have bubbled through to your conscious mind, you’re no longer aware that they are merely memories of the past or plans for the future, but have instead become lost in mental time travel.
