How was Vegito able to retain everything except his appearance after being downsized by Majin Buu in Dragon Ball Z?

In "Dragon Ball Z," Vegito retains his knowledge, experience, and abilities even after being downsized by Majin Buu due to the nature of the Potara earrings, which fuse two beings into one. The fusion creates a being that combines the strengths and traits of both individuals, allowing Vegito to maintain his power and intellect despite any physical changes. His appearance may have changed, but the essence of his character and capabilities remained intact because it is rooted in the combined attributes of Goku and Vegeta. This highlights the unique mechanics of the Potara fusion, where the fusion's qualities are not solely dependent on physical form.