Regretless square dance

Happiness. Sansheng is fortunate to meet you and love you all his life without regrets, which shows that the husband and wife are very loving and happy, and want to go on with each other, so it means happiness. Happiness is a peaceful and comfortable mental state, which can exist for a long time. The evaluation criterion is whether the target value (expected value) can be achieved. The key lies in the choice of the target value and the ability to achieve the target, which can only be achieved after they overlap, and the target value reaches the extreme value when it is equal to the upper limit of the ability.