NLP and coaching

For the first time when I came across with NLP (Neuro Linguistic Programming) in my life was when I attended in a seminar as a student at university,it was not clear for me at that time that how could it work,it was just a word untill I decided to be a coach,especially an international coach.
During a coaching session goals are set based on the clients values,usually clients are not commited to the goals which are not aligned with their values,on the other hand sometimes there are some beliefs and judgements that keep them back from moving forward.
But why people have different values?Where do the beliefs and judgments come from?
As a coach,do we have to know about all of those questions's answers?
We are trained to let the past and whatever related to it go,but to what extend we should let them go?
"NLP began as a model of how we communicate to ourselves and others which was developed by Richard Bandler and Jhon Grinder.This model explains how we process the information that comes into us from the outside.The belief is that:THE MAP IS NOT TERRITORY. And so the internal representations that we make about an outside event are not necessarily the event itself."Tad James,M.S,Ph.D
So it seems that as our beliefs and values mostly come from our past,our families, our culture and many other things such as our past decisions and experiences which obviously make our brains operating system,it will be a good idea to know more about them,at least whenever we are encountered with a client from a different culture.
Maybe it's better to take a look at their map in order to enrich it for them.
If you bring a computer to your office with an unfamiliar OS what would you do?
Do you change the OS or try to get to know it and learn how to communicate with it?