Today, I learnt that even when you are staring into space, your brain only consumes slightly less energy than if you were solving differential equations.
So where does all that energy go?
Your subconscious is hard at work, consolidating memories, making associations, and marrying the old and the new to create novel combinations.
The term unconscious mind is an insult to a part of the brain that does so much work behind the scenes.
Credit to Think Like a Rocket Scientist