What are some powerful quotes from "The Myth of Sisyphus" that illustrate the existential themes explored in the text?

One powerful quote from "The Myth of Sisyphus" by Albert Camus is: "There is but one truly serious philosophical problem, and that is suicide." This quote highlights the existential theme of the absurdity of life and the struggle to find meaning in a seemingly meaningless world. Another quote is: "The struggle itself toward the heights is enough to fill a man's heart. One must imagine Sisyphus happy." This quote emphasizes the idea that finding purpose and fulfillment in the face of life's challenges is what gives meaning to our existence.