This is where we work on different levels to let go of self and the unbeneficial actions that arise from an unbeneficial ego. On the emotional level the most powerful way to let go of selfishness is to develop the unselfish emotions. Development of the unselfish emotions helps us to let go of excessive attachment to self. With insight into the beneficial results of unselfish emotions, we gain confidence in letting go of self on a deeper level because we realize that focusing on self only creates more Dukkha and by lessening selfishness we walk on the path towards happiness.
This insight on the emotional level is very important to help us let go on deeper levels. If we are afraid that we are going to suffer by letting go of self, then there is no wish to do so. We may feel we have to defend ourselves, project ourselves or make sure that everybody sees us in a certain way to defend or protect our thoughts of self.
Insight on a deeper level cultivated with compassion and lovingkindness helps us to have compassion for others and to let go of the focus on "me" as being so important. This understanding brings spiritual happiness on the path to inner peace. With the confidence that arises from spiritual happiness, we are able to further examine the manifestations of ego on deeper levels allowing us to attach more to beneficial ego and let go of unbeneficial ego.
Why is it such a strong attachment? Sometimes asking why is a bit like a person who has been shot by a poisoned arrow. They are lying on the ground, dying. A doctor comes up and says, "Let me remove the arrow, I am a doctor, I can get the poison out". But the person says, "No. I want to know why this person shot that arrow, who they are, what caste they are, what village they are from," etc., etc. before they get all their answers, they die.
We have an ego - craving and ignorance fuel it. That is basically the teachings, craving and ignorance. Can we work to lessen them?