Good Old Sheldon is the second half of episode 7 of season 3 of My Life as a Teenage Robot.
Turns out, poor Sheldon was stuck on the aliens' ship when Jenny got rid of it (in the previous episode), and he's been spending decades trying to get back to Earth (even though it's only been a short time on Earth since he left). Hopefully, Jenny can get him back to his proper age.
- The Gobblin from the McDonaldland commercial makes a cameo appearance.
- Jenny's suit scheme, used to power Nora's age-regressing machine, is a self-reference to TRON.