The other day I came across a news item: Stephen Hawking is working on a new Theory of Everything. Fine. Einstein before him was wrestling with a similar one even when brought to the nursing home during his final illness. Think of Einstein working on a branch of Science and Stephen Hawking on another branch of a giant tree. The tree is one and our brain has capacity to store information but how much?
According to late Carl Sagan human brain has neurons 10¹¹ with circuits and controlling switches for electro-chemical activities; and every neuron has tiny filaments called dendrites connecting with one another. If we assign each of these connection to a bit of information it can hold only 1 % of the number of atoms that a salt crystal can carry! It is not really mind boggling if we understand the nature of humans to create an order from information the brain gathers.
If we go from a mere speck of salt to the universe we would need a brain as big as the universe itself! Our commonsense experience and evolutionary history has prepared us to understand our workaday world. But if we were to seek exoplanets and other universes these are not reliable guides. When we hit the speed of light our mass increases prodigiously while our thickness decreases to zero in the direction of the motion. Time will cease to mean anything. Without a tangible reference- the context of time and space, would the brain unravel the pulses of information to know anything?
In my view Theory of Everything is a misnomer. It should be qualified as thus: The theory what human reason only can digest.
Take a sample of a tree with an auger. It shall carry everything essential of the whole tree, but also climate changes, time etc.,
What you get of an object is not its material content but its context as well. This context is rooted in our intuition and commonsense experience and beyond. Reason in our workaday world can analyze the object but it is restricted by our own finite nature.
The Theory must go beyond it and also farther than reason. As finite beings we abridge Truth into workable truth that has limited use. So reason alone cannot get hands on Ultimate nature of our universe.