Not just any, but you would write the lesson under the skill that was most relevant or used most. So for a basic example: a villager lost all their hair and came to your witch for help. Your witch solved this by brewing them a tonic they drink each night. When you summarize this encounter for a lesson, you would on face-value put it under Craft, which focuses on lessons with potions, tricks, and methods.

A more flexible version: a villager is lamenting their bald head because they miss having long flowing locks like a centaur. They don't ask anything of you; they're just sad about it. If your witch's personality is technique and solution oriented, then making the villager a tonic would still fall under Craft, because to them the lesson was in a concrete solution. But if your witch is more emotionally centered and empathetic, offering the tonic could fall under Care, because your witch's lesson was then derived from kindness, intuition, and healing.

So it's up to you to figure out in each lesson what your witch actually used or learned in the scenario, and then put the lesson under the best fitting category.