Joel Larsen, a 35-year-old paper salesman, has a second chance to get his life right, thanks to a freakish accident that catapults him back to 1981, as a 14 year old. He is electrocuted, then wakes up in his teenage body, but with all his adult memories intact. Blessed with adult wisdom, though hampered by adolescent urges, Joel sets out to right the wrongs that will befall his family.

Joel has many opportunities to use his knowledge of the future to his personal advantage. He attempts to invest in Intel stock, and palms off 1990's pop music hits as his own; he sings Green Day's Good Riddance (Time of Your Life) at school, and turns in Nirvana's Smells Like Teen Spirit for a poetry assignment. He also saves his parents marriage by preventing an affair his mom has with his art teacher.