The idea for Catch-22 was based on Joseph Heller's personal experience in World War II. The feelings that Yossarian and the other bomber pilots felt were taken directly from problems he suffered while on duty. Heller flew 60 bombing missions from May to October in 1944. Heller was able to make it out of the war, but it took until 1953 before he could start writing about it. For this reason, the book contains references to post World War II phenomena like IBM computers and loyalty oaths. The war experience turned Heller into a "tortured, funny, deeply peculiar human being".
After publication in 1961, Catch-22 became very popular among teenagers at the time. Catch-22 seemed to embody the feelings that young people had toward the Vietnam War. A common joke was that every student who went off to college at the time took along a copy of Catch-22. The popularity of the book created a cult following, which led to more than eight million copies being sold in the United States. On October 26, 1986, professor and author John W. Aldridge wrote a piece in The New York Times celebrating the 25th anniversary of the publishing of "Catch-22". He commented that Heller's book presaged the chaos in the world that was to come:
The comic fable that ends in horror has become more and more clearly a reflection of the altogether uncomic and horrifying realities of the world in which we live and hope to survive.
Although Catch-22 is considered by many to be an anti-war novel, Heller stated in a talk he gave at the New York Public Library on August 31, 1998 that he and the other men he knew in World War II considered the war to be "noble" and "nobody really objected to fighting it". The anti-war reputation of the novel was fueled instead by the pacifist, anti-war ethos among young Americans surrounding the Vietnam War, which was in its sixth year when the book was published.