How do I explain this:
It is like standing on a slope and even with your eyes closed, you know that you are on a slope.
When I am facing North or South, I feel "balanced" and no longer have that sloping feeling.
And yes, I can never tell the difference between North and South.
A scientist would want to come up with some absolutely convincing tests of your ability. If you passed these, someone might like to test if you have any genes which are similar to ones essential for magnetic navigation in pigeons and magnetotactic bacteria. It seems plausible to me that this might be found. Apparently magnetite has already been found in human brain tissue. although I don't know if anything has been published on human magnetic navigation.