Exactly, that's what makes it so essential to understand. Just because there isn't a direct link between "need more salad" and the actual brain, doesn't mean th

Exactly, that's what makes it so essential to understand. Just because there isn't a direct link between "need more salad" and the actual brain, doesn't mean the connection is insignificant. Mood is still largely a mystery. Nobody understands fully why people can feel good one day or bad the next, and diagnoses of conditions like depression often miss small but significant things, like the result of a fatty dinner late at night causing poor sleep and a grumpy mindset the next day. We can't predict everything, but we also can't use that as a reason to ignore it.