I see people bringing this up sometimes but I think in the books there's a line by Bloodraven where he says that Bran will learn to ''see beyond the trees'' or some such. Here: "Once you have mastered your gifts, you may look where you will and see what the trees have seen, be it yesterday or last year or a thousand ages past. Men live their lives trapped in an eternal present, between the mists of memory and the sea of shadow that is all we know of the days to come. Certain moths live thei