One of the most interesting assertions in NLP concerns eye-accessing cues - the tendency for humans to look in predictable directions when they are thinking in particular ways.
NLP or Neuro-Linguistic Programming originated with two people who were in search of a way of modelling excellence - Richard Bandler & John Grindler.
Modelling is, essentially, the idea that excellence in any field of endeavour might be produced by anyone who wanted to achieve it, by identifying and then systematically reproducing its causes.
You are the owner and operator of the most amazing, beautiful, and complicated computing device ever invented - your brain.
When you buy a new camera, or a new printer, or a new microwave oven, you most likely take some time to look through the manual and learn about what your new purchase can do, and how to operate it and get the most use out of it.
Yet your brain did not come with an owner's manual (how many pages long would something like that be, anyway?). So it's no surprise that people have occasional difficulty controlling how their brain works.