I'll probably never understand how medical doctors manage to sleep at night, or how they managed to convince entire generations that the human body pushes butter directly into the veins. That's how they purport it at least. But always without any suggested mechanism for how the body processes dietary fat into calcium (the main constituent of cholesterol).

Cholesterol in the blood vessels is used to repair damage in the absence of the body's preferred repair tool: vitamin c, so I'm not at all surprised to learn it has an important role in brain function.