I've used the example of a tree for many years to illustrate the idea that there isn't just one real tree, but rather many trees, each with its own unique characteristics. When I mention seeing tall trees on the mountain, one person might picture oaks, another might think of Lebanese cedars, and yet another might imagine cypresses. Nobody would see the same image of trees that I saw.

That's because each person uses their own stored memories to interpret what things are. For someone who has never seen a tree, it would be impossible to imagine what image they could connect to the word "tree." Would they picture a cat, a book, or a bicycle?