This is kind of the other side of the "can you add skills with magic" debate. Can skills be permanently degraded or destroyed with PeMe spells? It seems like some skills, for example Area Lore, would be vulnerable to the destruction of memories. Other abilities, for example Athletics, might be governed by estimation and common sense, and would recover when the spell ended. However, most abilities seem like they would be somewhere in between. Messing around with the concept, I came up with this:
Mechanically speaking, what exactly would this spell do to a person's ability and art scores?
A&A has a spell called the Clean Slate that does this (p. 34). It gives a Year duration, stating that the target cannot relearn the skills lost during that time. He retains general Abilities such as language but loses everything else, including Arts. It notes he maintains his stored image memory in the form of his imagination, but lacks any connections or history around those images. Sounds kind of like sitcom-style amnesia to me.
How did I miss that? Thanks, I think youve pretty much answered my question. It sounds like a momentary duration spell would do pretty much the same thing, except without preventing retraining for a year.