[[WMG: Jimmy intentionality left the rocket for Sheen]]
* Then why did Jimmy leave all those notes telling him not to touch it?
[[WMG: The Yolkians will appear in a future episode]]
[[WMG: Sheen has been gone less than an hour earth time]]
So his parents and friends didn't even realize Sheen's absence. After all, that wreck of a show only lasted for one season.
[[WMG: Sheen comes back to earth someday.]]
Confirmed. An episode of ''WesternAnimation/TheAdventuresOfJimmyNeutron'' (The Tomorrow Boys) features a future Sheen working as a famous male model. This explains that Sheen ''did'' indeed return to earth. If he wasn't able to repair that rocket he crashed, then Jimmy must have picked him up. Either way, Dorkus must be so pleased that the bane of his existence has left.
** Maybe Nesmith was also picked up and brought to the zoo, jungle or space program he first came from.
[[WMG:Adding to the above, the series would have ended with Jimmy arriving to retrieve Sheen (and bring Nesmith and possibly Doppy with him)]]
Jimmy left notes specifically to keep Sheen from taking his rocket, so he most likely anticipated that Sheen would disregard this and hop aboard.
[[WMG: It was all in Sheen's head.]]
Not in the "he's really insane" kind of way, but just as "he's a kid with an overactive imagination" kind of way.
[[WMG: It's not the real Sheen who got blasted off. It's just a clone.]]
And said clone is actually the dumb one. The cloning process, however it happened, left Sheen smart enough not to touch the rocket or sneak into Jimmy's lab when Jimmy isn't there anymore. The clone unfortunately is not that bright and got himself into the mess that was this show. The reason no one seems to care is...well...it's a clone; plenty of time to go fetch him later.