The villain Patch blasts Astroboy with an iota ray-gun. While unconscious Astro is blasted into space. Luckily, the rocket ricochets back to Earth, and crashes into a far off country. When Astro awakens, he has lost his memory and is mistaken for General Astro, leader of a rebellion against a cruel dictatorship.
(Special thanks to Raquel in Alabama for setting me straight on this storyline. Seems my memory was scrambled by Patch's iota ray!!)