The point is not to ask what's in my power and what is beyond my capabilities and to examine everything that comes to my mind according to this procedure. The key is to actually focus on what's important in life, what does have priority and what is established by nature as the foundation of life.
I would agree that for the most part; however, the Stoics have no monopoly on what is usually ascribed to them:
Quote from Epicurus, letter to Menoikeuswhom do you consider is better or more powerful than one who holds pious beliefs concerning the gods; one who has absolutely no fears concerning death; one who has rationally determined the τέλος of one's natural state; and the one who grasps that, on the one hand, good things (namely pleasures) are both easily attained and easily secured, and, on the other hand, evil things (or pains) are either short in time or brief in suffering; someone who laughs at Fate which is introduced onto the stage of life by many as the mistress of all things? For that person, even though some things happen by necessity, some by chance, and some by our own power, for although necessity is beyond our control, they see that chance is unstable and there is no other master beyond themselves, so that praise and its opposite are inseparably connected to themselves.