CHICAGO (Reuters) - Approaching his 75th birthday, author Joseph Heller speaks and writes nostalgically about a childhood spent cavorting on New York`s Coney Island and a career that may have peaked in the 1960s with his signature novel, "Catch-22." Heller spoke glowingly of his 1961 novel about the stressed-out antics of U.S. Air Force bomber crews in Italy during the Second World War. "I won`t try to define `Catch-22,`" Heller told Reuters in his Brooklyn accent. "I believe the book remains relevant in so many ways because it deals not so much with the war situation but our societal situation (in) which people are at the mercy of other people." Heller was in Chicago recently on the first stop of an international tour on behalf of his just-published memoir, "Now and Then: From Coney Island to Here" (Knopf). In it, he touches on feelings about his early life playing follow-the-leader and more serious games on the streets, beaches and boardwalk of Depression-era Coney Island. He skirts through an adulthood that culminates late in the book on a Manhattan psychoanalyst`s couch, the point where the memoir becomes truly revealing. But both the man and his memoir seem to embody an ambivalence about whether to be forthcoming about his foibles. Readers learn little about his writing process - he painstakingly aims for two pages per two-hour working day. But any tidbit is illuminating. "I won`t get any idea until I`m bored, then usually it`s a single sentence," he said of the nuggets that become novels. For "Catch-22," the sentence that set the tone for the book popped into his head during a fitful night: "The first time Yossarian saw the chaplain he fell madly in love with him." "I can`t stay away from it because I`ve nothing else to do," he said of his writing. "I could go into a state of depression without anything to do." Heller divorced his wife of 35 years, with whom he had a son and daughter, and in 1987 married a nurse who helped him recover from a rare, paralyzing nerve disorder, Guillain-Barre syndrome, that struck in 1981. Heller gets a bit melancholy and curmudgeonly about the overall state of affairs. He sees an America rife with insecurity when compared to the ripe opportunities and camaraderie that blessed his generation. Heller insists he was not the model for Yossarian, whose terrifying wartime experiences led him to a crazy yearning for home that was stymied by an unpredictably shifty military. "I didn`t have any sense of being a person trapped in anything. I finished my missions and I was going home," he said.