David Johnson was born on April 7, 1963, in Missoula, Montana. As a child he attended C. S. Porter Elementary School and later attended Sentinel and would have graduated from Big Sky High School. Johnson's family moved to Corvallis, Oregon, in 1980, and he attended Crescent Valley High School, graduating in 1981. He was involved in a series of petty thefts as a teenager, primarily stealing soda pop and beer from local distributors with an assortment of childhood friends until one of them was caught and informed on the rest. He later detailed his experiences to reporters prior to the Barcelona Olympic games and used the material for his book and speaking tour as an example on how to turn one's life around.
During adolescence Johnson was afflicted with Osgood-Schlatter disease in both knees that kept him from participating in high school sports for the most part. During his junior high years he excelled in track, touch football and was on a Kiwanisbasketball team for two years. In elementary school he played organized Little Leaguebaseball and had some familiarity with boxing.
Even as a child Johnson was exceptionally fit and coordinated and lifted weights from a young age. In college at Azusa Pacific University he started to compete in the decathlon - at 6'4", he put his innate abilities and his constant physical training to use and began setting records. He graduated from the school in 1986 with a bachelor's degree in psychology, and later earned a master's degree in 2003 from the school in special education. After several years he was generally acknowledged as the best decathlete to date. At this time Dan O'Brien appeared on the scene and began to provide Dave with his first real competition. O'Brien and Johnson became good friends and consistently placed first and second in most events. O'Brien eventually began to be considered the best overall decathlete, but Johnson earned the recognition as the best ever at 2nd day events. Johnson was a member of the 1988 U.S. Olympic team.
For the 1992 Summer Olympics Games the team of "Dan & Dave" was promoted as the real competition in the games and the question of who would take first and who would come in second was widely debated. Dan failed to qualify for the team when he no-heighted on the pole vault, leaving Dave as the presumed gold medal winner. Unfortunately for him, Johnson experienced a stress fracture in his left foot on the first day of events. He put on a shoe two sizes larger, laced it up tight, and competed anyway and won the bronze medal. Johnson's endorsement career continued for at least another year after the Barcelona Olympic Games and included Oakley Sunglasses, Pert Shampoo, Ryder Trucks, and Reebok shoes among others.