Only some billions of years of evolution and a lifetime of knowledge abut how our world looks like! When you see a picture of a cat your brain has a whole lot of context to put the picture into: it looks like some live creature, has eyes, legs, you can tell where it's head is, you can imagine how the fur feels like etc.
An untrained neural net has to learn everything from scratch (ha!), from pixel values to "knowing" what a cat is. There is some work on decreasing the amount of data needed to learn, but it's a very tricky subject.
An untrained neural net has to learn everything from scratch (ha!), from pixel values to "knowing" what a cat is. There is some work on decreasing the amount of data needed to learn, but it's a very tricky subject.