After you grow up, you become independent. Independence is a state where you will try to understand yoursel better, make your own decisions and solve problems.
Same thing happens when you undergo psychotherapy. You will develop insight, independence and self respect. You might doubt some irrational systems which you had believed earlier, based on rationality.
In this phase, you are trying to liberate yourself just like a bird flying from nest after getting wings. There is a risk at this point. You might get easily trapped into another false belief system. If you are not fully equipped, you might just fly and reach another nest, rather than making your own nest. So you are flying from one nest to other nest, nothing changes in your life. Therefore you should terminate therapy only after building your own nest. That is, only after aquiring independent and rationality.