An interesting question. A million input neural network isn&#x27;t necessarily absurd. Images are very high dimensional. One could easily imagine a one megapixel input to a neural net. But in natural images no single pixel is indicative of any single image characteristic by itself. I think this isn&#x27;t a coincidence but a common characteristic of &quot;natural&quot; high dimensional data, on which neural nets tend to work well. So yes, I&#x27;d say what you&#x27;ve described is not likely for a large category of &quot;natural&quot; high dimensional data which probably includes most of the data we care about in the real world.