The stable diffusion model is only 4GB, yet its enough to describe almost anything visually. Its also an extremely size-unoptimized model.

Now the 800MB is mostly spent on other things, but even 8mb, if optimized enough, is plenty to encode a vast amount of visual information into our brains, including a hyper-efficient-accurate human face recognizer, a hatred of bugs/mice/spiders/snakes, a liking of fluffy and shiny stuff, etc.

There is epigenetics, microbiome, and some other stuff as well.