Jean-Paul Sartre's philosophical ideas were considerably shaped by significant life events such as his experiences in World War II, which influenced his existentialist views. Growing up with a strong intellectual background, he initially engaged in academia but felt constrained. His wartime experiences, including captivity and observing the absurdity of human suffering, pivoted his thinking towards themes of freedom and responsibility. The profound impact of existential crisis forged the foundation of his works, like "Being and Nothingness," encapsulating the struggle of human existence. Such experiences were critical in shaping his belief that individuals must create their own essence through choices.