In Jean-Paul Sartre's book "Nausea," the narrator reflects on the nature of existence and consciousness. He suggests that his ability to think is what affirms his existence. This contemplation brings him a sense of horror, as he realizes that his very act of thinking is both what defines him and what creates his discomfort with being alive. The struggle with this awareness adds to his feelings of existential dread.

The quote encapsulates the paradox of existence: the thinker cannot escape the burden of thought, which both gives life meaning and invites fear. The narrator feels compelled to confront his own existence, challenging the emptiness and striving against the void that he perceives. Ultimately, it is the tension between thought and existence that fuels his journey through the complexities of life.