- Totally Spies!: "what if... Sam couldn't be mentally changed back" (Episode Child's Play) [given by wildfire377 from AO3]
when Vladimir in his childish state reprogramed the toys to undo the mind altering there turned out to be a problem with returning Sam to normal, he had designed the toys to effect adult minds, not a teenagers, this meant that he couldn't undo it on Sam, once Jerry was returned to normal he confirmed what was said, but he could unlock Sam's original mind to return her thoughts and memories, once done so Sam came back but with a childish nature to her, along with an interesting side effect.
it seems due to her mind being regressed to that of a child she had regained the enhance learning children had at young ages, this combined with her teen knowledge and memories has allowed her to learn all kinds of things at a very heightened rate, she learnt to play the basics of 4 instruments in 2 weeks, advanced electronics and physics in 1 week and so on, this allowed her to help in missions and even make designs for new gadgets which Jerry was impressed by, though most of them seemed to be based on and act like children's toys.