Human adventurer getting transformed into an elf and suddenly they feel like a kid again because they're not 100 years old yet. Everything that a human picks up in their first few years of life can take an elf decades to truly master.
Controlling their emotions becomes so difficult. Feeding themself is tough. All the noises and intense lights are so overwhelming to their new senses. It's too much!
Most embarrassingly of all, their potty training also went bye-bye along with everything else big about them.
Fortunately, their adventuring party found them a lovely elf couple in the nearby town who agreed to look after the elven kiddo. It should only take 50 or 60 years to get them potty trained, if they're a quick learner anyway.
The adventuring party comes to visit their little mascot every few weeks bringing all sorts of treats and stories (although they edit out all of the gory details for the baby).
