It certainly is a mystery but always right. I've always been sorry when I haven't listened to it.

its just self-preservation and as you say invaluable.

Two voices inside us. One says yes-the other no.

The mind is a vast library just imagine every image is printed in the library so there will be times when it overlaps and you get mind giving you answers sub consciously and consciously

I think what we learn and experience is embedded in us, and forms the basis for our intuitions. Whenever we experience something new, or run into a problem in which we don't see a logical solution it functions as the "what if" of our imagination, tempered by what we know.

Intuition is simply the operation of one's unconscious mind, which has way more going on than the vast majority of us are aware of (or want to be aware of). It is like a background process on a computer.

It is often right and often wrong. The unconscious is not very rationally discerning, is quite gullible and suggestible, and yet it is also aware of a lot of connections that don't rise to the level of consciousness. I think it is most useful in guiding us in those areas that we tend to overthink consciously, particularly when they make us resistant to change or to things we know we "should" do but carry some risk or loss that we fear. Those tend to represent the situations where you say, "I wish I had listened to my gut". Or your conscience, or your "higher self".

The canonical example is that no one, on their death bed, says "I wish I had attended more business meetings" or "I wish I had bought that Maserati". They say things like "I wish I had been kinder" or "I wish I had been more present for my loved ones" or "I wish I had played more with my children" or "I wish I had risked getting to know so-and-so" or "I wish I had known myself better" -- things like that. I think the unconscious tends to stay in touch with those things better, while our conscious mind is constructing a million reasons why we need to conquer, acheive, acquire, win, compete, plan, strategize, execute and just generally "do" rather than "be", to acquire status rather than character, etc.

One of the best books on the subject is The Gift of Fear: Survival Signals by Gavin DeBecker.
[amazon.com]

Naw, that's just the latest Google update.

My brain. I call it my inner critic. Unfortunately it is always a day late and a dollar short... :/

Well, since this is a site for agnostics who really are mostly atheists, I'll say that your intuition could be your subconcious or instinct. This is a survival instinct, which pretty much (for most people) works in the background, and comes forth when a situation arises wherein it is perceived to be necessary. At least that's my take.