"Captain Jack" is an anti-drug song, written in late 1971 when Billy Joel observed suburban teenagers buying heroin from a dealer across the street from his apartment. He described it as a "brutal" song about coming out of the New York suburbs, but a situation he'd seen replicated across the country. Joel emphasized that the song depicts a "pathetic loser kind of lifestyle," stating that it’s about the tragedy of affluent young people turning to drugs, and how many of his own friends were lost to addiction. It plays as a stark commentary on the hidden struggles beneath a seemingly comfortable life.