When Breath Becomes Air is a heart-wrenching memoir written by Paul Kalanithi, a neurosurgeon diagnosed with terminal lung cancer at the age of 36 when he is about to complete his 11 years of medical training. The memoir unfolds the tale of his life through two main threads: the first half with him becoming a doctor who is dedicated to saving the lives of others and is well-devoted to neurology, whereas during the last half, his character transitions into a patient battling cancer and staring death in the face. Many profound ideas are present in this memoir, such as the theme of confronting death and altering perspectives.

As a medical student and a resident, Kalanithi constantly deals with death. He soon gets desensitized to dead bodies after all the lessons dissecting cadavers and experiencing his patients passing away when surgeries or other treatments are ineffective. Aside from his work, Kalanithi also frequently perceives death in his surroundings. His former medical school friend dies in a car crash; his other friend and colleague, Jeff, commits suicide after losing a patient; his colleague, V, is diagnosed with pancreatic cancer. Though V has been cured, the potential and reality of death become sharper in focus for both V and people who work with him.

Kalanithi expresses that “Death comes for all of us. For us, for our patients: it is our fate as living, breathing, metabolizing organisms. Most lives are lived with passivity toward death -- it's something that happens to you and those around you.” This quote indicates that he is well aware that everybody will eventually die one day, and he is constantly in touch with death, though it still seems quite abstract to him. He had prepared to be a neurosurgeon for a decade of his life, and had all those ambitious plans under the unconscious assumption of longevity, just like any ordinary person. The moment he knows with certainty that he has cancer, death is more of a concrete reality; he knows for sure that he doesn’t have much time left within the considerably short lifespan of a human being. After hearing the news, he is miserable because all his ambitions and plans for the future shatter into pieces.

Kalanithi’s role alters completely after his diagnosis. As a physician with expertise in the field of neurology, he tries his best to save patients from the scythe of the demon, and help patients who come face to face with their own death to accept the reality and give them glimpses of hope to keep the patients’ physical and mental state at a decent, healthy level. However, he transforms into a patient approaching death, which creates some mental conflict; he knows his physician's words too well, as he previously says similar things to his patients. He knows that not knowing the approximate statistics on how long he has left would bring optimism and hope, positively affecting his recovery. Still, he knows this is only a delusion for the patient to be confident, and he believes that his doctor role should allow him full knowledge about his health. Without any sense of how much time he has left, he can’t get a good grasp on what he would like to do or could accomplish. Within this unknown time scale he doesn’t know what kind of project he could finish. He cannot decide which plan to implement since he considers that ‘if I had two years, I’d write. If I had ten, I’d get back to surgery and science.’ He direly wishes that his doctor role could perform some of its privileges, but the conflicting part is that he is now taking the role of a patient, not a surgeon.

Kalanithi said that ‘the fact of death is unsettling, yet there is no other way to live’ gives an insight into his attitude towards death, which is to accept. He said, "even if I’m dying, until I actually die, I am still living.” The lesson he understands during the last periods of his life is that he should enjoy the present and pursue what he thinks is meaningful. So he decides to write this memoir to keep a record of his existence for his daughter, to display his reflections upon his own life, and to leave behind a legacy through which he can positively impact the world once he is gone, which is indeed a compelling one.