True self is a psychological term that was coined in the 1960s. Unfortunately, someone who is a true self may be experiencing narcissim where the person thinks very highly of themselves. To be a good true self, it is better to refrain from going as far as narcissism. Instead, it is best to be awake and doing things that appeal to you.
On the other hand, the opposite of true self is false self and it is where they do not have the initiative to do the things that they want to do. True self is believed to begin when someone is a baby. Over time, the true self can change where the person realizes that there are others in this world.