HOW THE BRAIN WORKS
THE SHORT VERSION
IT ADDED PARTS OVER TIME
Your brain evolved, causing what worked to continue onward and get better. The primitive first part is the very simple reptilian brain, then the emotional brain (a next level up) and then finally the one that actually caused us to survive (as the human population almost became extinct, with only 10,000 alive at our low ebb).
THE CLEAR FUNCTIONS OF THE BRAIN PARTS
The highest level of the brain is the thinking brain, where we can proactively figure things out beyond the simple, straight-forward more mechanical brain functions. The lower levels of the brain are "reactive", focused mostly on preventing our non-survival. They have old pictures of what has occurred. The pictures that are more dominant are those that involved an emotional charge that caused them to be more deeply imbedded - they were, of course, generally more important to our survival.
The reactive brain reacts with pictures that are coughed up from what is seen as what matches what is going on and which could affect survival. ("retrieving bits and pieces of files stored all over the brain" - Ford, op.cit.) The brain's memory pulls up bits and pieces that relate and are not complete in and of themselves, but which get "integrated" together. The mind works much as visual center of the brain works. It receives information and then puts it together into a consistent picture so the mind thinks it sees the "whole picture", but it doesn't. You see, much like our minds, there is a blindspot in our eye, where the retinal nerve attaches (so there are no light receptors in that spot), yet, what we think we see has no gaps in it. The same goes for our thinking.
INFORMATION IS NOT "THINKING"
When we don't know where the information comes from, we have an "intuitive sense" that we know something. That intuitive sense, and the information behind it, are, of course, indicate possible bits of useful information. Intuition and other lower brain functions are often conjured up to have "super-knowing" and/or "super-intelligence" - and then we attribute also a "will" and intention, and then fill in our full picture by creating some magic to them.
However, the lower brain functions, which have enormous and essential importance, of course, are still lower brain functions - they operate at a much, much lower "intelligence", often with no ability at all to reason or discriminate among facts or fiction. But people will swear that intuition and the subconscious brain are powerful and determinative, defending that assertion emotionally, as if it were threatening and was part of their identity - this is, of course, a product of the emotional and reptilian brain. The fact that people make these things up and believe them is all a part of what is explained in The Believing Brain piece. (It is important that you understand this, as not knowing it might open the door for you to make ill-advised decisions based on an a fallible source that is prone to lack of screening through rationality and facts.)
THE DEFINITE WINNER AS TO ADDED VALUE IS...
The "secret" to a good life is to optimize the partnership between the lower mind and the higher, thinking mind. One will not have a good life if one is simply run by the reactive, lower minds - one would never let them manage your life or run things, as they are more like children running amok. It is the higher brain that must be in charge (as often as is needed!) (Read Using The Higher Brain As It Should Be Used - The "Secret" To A Greater Life.)