I turn to a book I wrote about ten years ago.

The Brain is efficient:

It is smarter than supercomputer but uses ~100,000- fold less energy and space.

Our brain uses 20 watts, and only occupies 1.5 liters of space.

This is fostered by 10 principles of efficient design.

Our Body uses 80% of total energy so it too must be efficient.

Let’s consider what we get for free: Basically, we get energy from Brownian motion (thermal noise).