I'm not sure if this is the same thing, but let me describe what I have experienced and see if it relates. This was an experience actually prior to lucid dreaming. A couple times I have really looked at my surroundings and suddenly had a feeling of "connectedness" to everything. The space between me and other objects was almost material rather than empty space. Or like seeing everything as a whole...like a painting only in 3d. I felt great peace and a feeling of belonging. This is not unlike the feeling I have in lucid dreams. This is why I also feel a sense of loss when I wake up from an LD.