Neuro linguistic programming - what a horrible term! It shows where it came from - West coast America. But put aside the negative reaction. What is NLP? It's a systematic way of noticing how people communicate. It's a way of attending to all the various indications people give of how they understand the world, and their place in it. Some of these cues are neurologically-based. Others are linguistic, i.e. based on the minutiae of the language someone uses: hence the term 'Neuro-Linguistic'.
Because life is so stimulus-rich, we all make simplified mental representations of what seem to us to be the key elements of our own personal experience - in other words, we make 'models of the world'. Having built up a 'good enough for the moment' model of our world, we then live in accordance with it. We interpret new information in such a way as to make it fit with our pre-programmed model. If there are shortcomings in our internalised model - if we have over-simplified or misrepresented our past learning experience - we run into problems dealing with new situations. New truths won't fit with old models.