Hi ...Vesuvius. Nice question, especially since I was pondering over a very similar question a few months ago. So if you will allow me, may I share my thoughts on my original problem as an answer to your question?

I was wondering how we arrive at knowing the limits of our own potential at any given stage in our life. Which actually came from a notion I had years ago that "we are incapable of thinking beyond the limits of possibility". What I mean by this is not Physical possibility, but manifest able possibility including thought forms that expand multi dimensionally.

So after letting this question rattle around for a while an idea came to me. I don't know if it is the right answer or if it is capable of satisfying our constant need for tangible & verifiable solutions to our thoughts.

It is best illustrated with a situation.

Imagine that you are making a speech to an audience about this subject and you make the statement "We are capable of manifesting anything in life".

Intending to stump this statement an individual (a smart ass) in the audience shouts out, "Hey if that is true are you saying that I can instantly grow wings & fly like a bird?"

Now you have a problem. Because both you and the other person know that it is impossible to instantly perform that feat.

Now here is my observation on this situation. Because I believe the answer exists in this example. I think the consciousness within us always knows the invisible line where possibility ends and impossibility begins.

It is the very existence of this inner knowingness that allows the "trouble maker" in the audience to know what example to present so that it is a clearly impossible task.

It is as-if the person asking the question commands their inner consciousness to give an example that is beyond what is possible, and instantly the example of growing wings and flying leaps forth within their consciousness in response to that command.

If you observe the movement of your own thoughts & emotions you will notice that we are hardly moved by things that are beyond our potential. We never worry about dreams that are impossible because we just don't give a damn about them.

Instead we worry about dreams that are possible because deep inside we know that they are within our potential & literally came to us because we were the ones chosen to manifest those dreams.

It is our own fear of failure that often keeps us from going after our own potential.

It seems that we constantly suffer & triumph within our potential of possibility.

Perhaps your thoughts on this idea are different?