The Basis of the Self
"I think, therefore I am" is the statement of an intellectual who underrates toothaches. "I feel, therefore I am" is a truth much more universally valid, and it applies to everything that's alive. My self does not differ substantially from yours in terms of its thought. Many people, few ideas: we all think more or less the same, and we exchange, borrow, steal thoughts from one another. However, when someone steps on my foot, only I feel the pain. The basis of the self is not thought but suffering, which is the most fundamental of all feelings. While it suffers, not even a cat can doubt its unique and uninterchangeable self. In intense suffering the world disappears and each of us is alone with his self. Suffering is the university of egocentrism.
Milan Kundera, in 'Immortality'