The Second Reality :
The cause of suffering, which is to be eliminated
Suffering

We have already recognized that suffering is expressed as grief, lamentation, pain, distress and exhaustion. This suffering was experienced due to meeting the unpleasant birth, ageing, sickness, and death; parting from the pleasant youth, health, and life; and the inability to obtain what we desire, which is permanent youth, permanent health, and permanent life of the body. 
Suffering is birth, ageing and death of the “self.” It is parting from youth, health and life and meeting of old age, ill-health and death. It is the inability to have what we want, which is eternal youth, health and life. We know this is possible only in the fantasy of Heaven. In addition, the inability to have what we want includes all the daily frustrations and disappointments that we experience throughout our lives. 
What then is the cause of this suffering? Is it because we have a “self” that grows old, falls sick, and dies? 

What is the “self” that really grows old, falls sick and dies? 

Is it the body that is the “self” that grows, old, falls sick and dies? 

How did this body become the “self” that grows, old, falls sick and dies? 

Because I personalized the body, thinking “this body is mine,” it is my “self” (upādāna). 

If I did not personalize the body, this body will “not be me.” 

Then the ageing, sickness, and death of the body would not be my suffering. 

Included in the body are the feelings, sensations, concepts, and perceptions. 
It is important to understand that the personalized constituents of perception are the foundation of the insecurity of life (sankhitthena pañcupādānakkhandhā dukkhā). In other words, it is the notion of “self.” (sakkāya diṭṭhi and mana). The ageing, sickness, and death become a suffering only because it is connected to the self, and not otherwise. 2. Suffering also occurs when the Self is in emotional relationship with the world in the form of lust, hate, fear, and worry. 3. Suffering also arises due to insatiable desire for material gains, variety, sensual pleasure, fame, power, conflict with others, comparison with others, etc that cause suffering.