A sizeable amount of research into affective forecasting has shown that we overestimate the affective impact of future events. Both in duration, and intensity.
When assessing the emotional aftermath following a “negative” event, such as losing a job, it has been consistently observed that a subject’s belief as to how ruinous this will be to their happiness is inflated. The firing will not sting for as long as is predicted, nor will it be as severe. 
This also works for the reverse. Using the example of winning the lottery, the level of expected happiness exaggerates the acuteness and underestimates just how quickly it will return to baseline.