Goodnight was born to Albert Goodnight and Dorothy Patterson in Salisbury, NC, on January 6, 1943. He lived in Greensboro, NC, until he was 12, when his family moved to Wilmington. In his youth, he often worked at his father's hardware store. Mathematics and chemistry were Goodnight's strongest subjects in school, thanks in part, he says, to a "wonderful chemistry teacher" at New Hanover High School.