I can understand this in a way as I have been a deep fantasizer since childhood. I believe it is a coping mechanism for a less than fulfilling emotional situation or situations experienced in life. People who are deep fantasizers, I think are probably deep people who for whatever reason need more than the standard amount of emotional support from others and because they don't get that they begin to create an alternate reality where all of their needs are met. A place that they can escape to where they are appreciated, admired and above all loved in such a way that that place is preferable to their real life. So preferable that they would swap out their real life for it in a heart beatif they could. Anyway, that's my take on it. As I've grown older I don't do this nearly as much any more unless I'm maybe alone and relaxing with a good day dream. I can spend hours just day dreaming and going anywhere I want to in my own mind. I think that fantasy can be a healthy thing as long as you keep in mind that it is just fantasy and not let the perception of it cross over into reality.