You say that like it is a bad thing. Research shows that people with a greater grasp of “reality” are less happy. Science is about facts, and facts don’t care how you feel; A positive mental attitude is about focusing on ideas that bring you contentment in life. Your negative thoughts might be “right”… but if they are not productive, or actively harmful, then how is that Better than constructive self-delusion? Go ahead, tell your nephews and nieces that Santa isn’t real; Your family will love you for that come Christmas. /s