The pleasure and suffering are part of the duality. The duality is mere illusion form ultimate standpoint. If one tries to search the source of the mind than it leads him towards the soul. The soul is the innermost self and the source from mind arises and subsides as the universe.
Siddhartha the prince with all his comforts of luxuries, when he saw the suffering he renounced all the pleasures of life and try to seek the truth of life. When he became aware of the true self, he became aware of the fact the life is nothingness. That is everything was created out of nothingness or formless consciousness and everything is nothingness or formless consciousness.
Modern man is pleasure hunter, and wants only pleasure of life not pain. Thus everyone is involved in hunting the never ending pleasure, and they try various methods, which suits to their own mindset, to get that pleasure that does not pass away.
When one who is able to think, very deeply, will find the fact that, the pleasure and pain are created out same substance. And the nature of the substance is formless. The formless substance itself is the true self. The true self is the source of the experience of diversity (mind or universe or waking). The whole experience of diversity (I) is erupted out from this formless source.
Since man thinks he is an individual separate from the world and limits, the mind (I) to the physical entity, he remains in ignorance, and experiences the duality as reality. Thus he accepts the suffering as part of his life.