Thinking 'there's an ear, and it hurts' rather than thinking "my ear hurts" is a proper method. Similarly, viewing anger & fear as merely elements of anger & fear will make them go away & make the mind calm again.
Regarding the primary question asked, the suttas contain the stock phrase:
Yadaniccaṁ taṁ dukkhaṁ;
What is impermanent is unsatisfactory.
yaṁ dukkhaṁ tadanattā;
What is unsatisfactory is not-self.
Thus, the Anatta-Lakkhana Sutta begins the wisdom inquiry with impermanence. The Buddha asks:
- Now, that which is impermanent, is it unsatisfactory or satisfactory?
- Now, that which is impermanent, unsatisfactory, subject to change, is it proper to regard that as: 'This is mine, this I am, this is my self'?
Therefore, here, impermanence takes a significant focus. Once impermanence is clearly discerned, it is plainly obvious that which is impermanent, subject to change by the forces of nature; subject to change beyond our control; that which also cannot be relied on for lasting happiness; certainly cannot be regarded as "This is mine" because what is impermanent can be subject to change & loss anytime.
The five aggregates are like "borrowed goods". The five aggregates do not belong to anyone. The five aggregates are just creations of nature. Therefore, the suttas contain such phrases as:
Nāyaṁ, bhikkhave, kāyo tumhākaṁ napi aññesaṁ
Mendicants, this group (kaya; of aggregates) doesn’t belong to you or
to anyone else.
SN 12.37
Therefore, bhikkhus, whatever is not yours, abandon it; when you have abandoned it, that will lead to your welfare and happiness for a long time. What is it that is not yours? Material form is not yours. Abandon it. When you have abandoned it, that will lead to your welfare and happiness for a long time. Feeling is not yours. Abandon it. When you have abandoned it, that will lead to your welfare and happiness for a long time. Perception is not yours. Abandon it. When you have abandoned it, that will lead to your welfare and happiness for a long time. Formations are not yours. Abandon them. When you have abandoned them, that will lead to your welfare and happiness for a long time. Consciousness is not yours. Abandon it. When you have abandoned it, that will lead to your welfare and happiness for a long time.
MN 22; also SN 35.101 regarding the six sense spheres
While direct estrangement (nibbindati), i.e., seeing the five aggregates as 'alien' (parato), can certainly occur when the five aggregates are clearly seen with a clear mind as being merely aggregates & elements (dhatu), suttas such as the Anatta-Lakkhana Sutta and Sīlavantasutta include impermanence & unsatisfactoriness because this is a natural gradual way to feel estrangement. The Sīlavantasutta says:
Sīlavatāvuso, koṭṭhika, bhikkhunā pañcupādānakkhandhā aniccato
dukkhato rogato gaṇḍato sallato aghato ābādhato parato palokato
suññato anattato yoniso manasi kātabbā.
Venerable Koṭṭhita, a virtuous monk is to wisely pay attention to the
five components of attachment as impermanent, unsatisfactory, disease, cancer, stabbing, misfortune, affliction, alien, disintegrating, empty and impersonal.
For example, in AN 3.39, when young Gotama realized he would be subject to aging, illness & death, he lost the pride (mada) associated with his youth. This is an example of estrangement arising primarily from realizing impermanence & unsatisfactoriness; which naturally reduced the pride of self in young Gotama.
Or MN 54, as summarised in MN 22, goes into detail about why sensual pleasures provide little gratification, much suffering and despair, and that the danger in them is still more. When clearly seeing the unsatisfactoriness of sensual pleasures, which is related to their impermanence unable to sustain lasting happiness, an estrangement from sensual pleasures occurs. MN 22 summarises:
The Blessed One has stated that sensual pleasures provide little
gratification, much suffering and despair, and that the danger in them
is still more. With the simile of the skeleton…with the simile of the
piece of meat…with the simile of the grass torch…with the simile of
the pit of coals…with the simile of the dream…with the simile of the
borrowed goods…with the simile of fruits on a tree…with the simile of
the butcher’s knife and block…with the simile of the sword stake…with
the simile of the snake’s head, the Blessed One has stated that
sensual pleasures provide little gratification, much suffering and
despair, and that the danger in them is still more.
MN 22
Therefore, in conclusion, the Dhamma shows it is not only the perception of non-self (anatta) that generates estrangement (nibbindati). The perceptions of impermanence & unsatisfactoriness also significantly contribute.