How rare are shared dreams?

Two affianced persons dream on one night—the one sees her future home, a humble one—the other sees his future home also, but one, of a more pretentious order, how is it that these two should have such a similarity of dream, and yet different, on the same night?

According to my philosophy of dreams, those you refer to come from an outside source. The variation in the dream—or vision of the future home is caused no doubt by the difference in temperament of the persons' dreaming. For example, you and I might look at a building and each of us give a description of it, but it would be found that looking at the building, each from his own standpoint, your description and mine would be different, and so in the case of the two dreamers—both had the spiritual vision of a future home placed before them and according to the individual, so was the impression of the vision. In the one case, the controlling spirit endeavoured to excite a little ambition in him—to push him forward—in the other, the picture was given to show that peace and happiness may be obtained even with a humble cottage for a dwelling-place.

—Hafed, Prince of Persia