Recently I discovered that I've shared believes in this philosophical direction since my teenage works (found how it's called).
One introductory term - "paradoxical universality of brain" - brain is specialized in being universal.
The estimation of brain's enormous computing power and memory are arbitrary/not really practical, because brain power is not comparable to computer power. Computers are in fact more flexible and more "universal" than brain, and the ultimate cognitive system is a brain (generally intelligent agent/core, AGI) + a computer and external memory (neither a brain alone, nor a computer alone).
However, you can use a computer to simulate a brain if you have a precise model and speed, but you can't use a brain to simulate a computer, even if you have precise model - most brains are incapable to simulate on their own even the first mechanical computers (say, those which multiplied), logarithmic rulers and artillery tables with precomputed values, and also the papers to store reliably phone numbers or a line of text.
These external "tools" are in fact extensions of our brain - they are just accessed differently than memory which is internal - the access passes through motion (translation), which in fact is just the lowest level of output that the system produces, it's output of data to the physical reality and translation of data in physical reality. At the lowest level output should be decoded down to the "machine code of Universe", the "language of the particles" (my terms).
That's the same as the memory hierarchy in computers - from the fastest registers, to different levels of caches, RAM, hard disks, Internet to external media which requires to be physically moved in order to get accessible.
Culture starts from the changeable and stable intentionally altered and structured environment which allows artifacts/memory to survive longer than a brain and outside of a brain - that includes the overlapping lives of the different generations allowing language to be transmitted.
A human brain alone, without the external tools, without alterable structured stable environment, without intelligent beings around to teach it stuff and especially to teach it sophisticated language... In this conditions it wouldn't go much further than a chimpanzee's brain in similar conditions.