Hmmm, I am all for imagination and encourage my DD to tell stories, pretend, make up songs, etc. and she seems to have a great imagination, but if she were not able to distinguish play from reality, etc. I think I would put less empahsis on encouraging imagination and more on making the lines between his imaginary experiences and his real ones. I have a vivid imagination and it served me well when I wrote and had work published, but it can also be a burden and can get activated by worry etc. so I think it is good for him to understand some boundaries around his perceptions.
Perhaps he has had vivid dreams and we probably have all had dreams that seemed so real, but it sounds like it happens more often with him so I might
