Freud divided psychology into three different but related parts, ego, id and superego. If you say that you are the happiest, I am afraid that the most appropriate thing is to fall on the "ID". Freud believed that the ID consists of two parts: life instinct (such as hunger, self-protection and sexual desire) and death instinct (including attack and even suicide). Like a wild animal, it only knows how to satisfy its own desires and follows the "happy rule", that is, if it can satisfy its own desires, it will not do it. Of course, the id usually operates at the unconscious level and will not be realized by us. Only when the superego's supervision efficiency drops, it is possible to release a little control of the ego. This can also explain why serious mental patients are prone to go crazy and hurt people.
However, if we only understand this sentence as my blind satisfaction with desire, it will be as extreme as Freud. Freud's theory is really good, but when he gives psychological analysis to patients, he still uses the initial instinctive desires to analyze them, without paying attention to what these instincts have turned into after social and educational factors. This is the part that is usually displayed under the supervision of the superego.
It should be said that ID, ego and superego are all part of us. Id is a selfish beast, ego is the executor of personality, and superego is the model of conscience and ego. The phrase "be a happy self" should not only fall on the keyword "happiness", but also fall on the keyword "self".
Then what is "self"? Generally speaking, this ego is mostly a mortal formed by the struggle between angels and demons-ego, not ID or superego. In this way, this kind of "happiness" will be fundamentally changed-not only to satisfy the desire, but also to complete the task of superego-to win the respect of others and make contributions to society.
For example, Guo's blood donation has nothing to do with his instinct. Remember his slogan? "Helping others is fun." This is not just empty talk and slogans. By doing good deeds, he can experience real happiness.
So simply speaking, "being a happy self" includes the satisfaction of the instinctive desire of the id, the realization of the moral goal of the superego, and the final choice made by the ego under various constraints. In any case, it is a "happy" self in the end.