Kiki's Delivery Service
Kiki losing her powers is not a plot point. It is the film's entire thesis. Every person who has ever been good at something and then suddenly wasn't will know exactly what the film is talking about. The recovery is not dramatic. It does not arrive through a speech or a revelation. It arrives through the specific stubbornness of someone who decides to keep going when there is no visible reason to.
Miyazaki made this in 1989, the same year he co-founded Studio Ghibli as a going concern. It was the studio's first major commercial hit. The version the fansub community circulated - before Disney's English release, before the Phil Hartman dub - preserved the original Yamamoto score that Disney later replaced. Both versions exist. Only one of them is the film Miyazaki made.