There's No Place Like Springfield: Part 1 G.I. Joe : Season 1 Episode 54

Shipwreck and Lady Jay go on a mission to pick up a scientist who claims to have developed a new weapon. When they find him, he implants the secret formula into Shipwreck's brain, which can only be released by a secret code word he gives to Lady Jay. As they try to evade Cobra, Shipwreck is knocked unconscious. When he wakes up it's several years later, the Joes have defeated Cobra, and he's married to Mara. He tries to remember/figure out what happened during the missing years.