I'd argue that the memory of a smell is as visceral as the memory of a color or sound, which is not very. The difference is that smell is so much more powerful

I'd argue that the memory of a smell is as visceral as the memory of a color or sound, which is not very. The difference is that smell is so much more powerful in reality that we see through the memory-representation for what it is, an empty placeholder. When we smell fresh bacon in the morning, that experience can be all-encompassing. The same is not true for the optical experience of the thing. With colors and sounds we are merely less aware of the qualitative emptiness of their mental objects.