Some of the people pet the dog because they think it is cute, some of the people are afraid of the dog so make an effort to avoid it, and some people hardly notice the dog at all because they are too busy talking about Jersey Shore and The Bachelor.
As soon as the dog leaves, you ask each of the people in the room, "What is the dog really like?"
One person says, "Really friendly and cute." If we are trying to determine the reality of this dog's personality and existence, I am inclined to believe this person, because she actually petted and touched the dog and the dog did not bite her. Isn't this evidence of it's existence as a friendly animal?
Another says, "Really terrifying and vicious." If it is true that the dog is really friendly and cute, this does not explain why some people are still afraid of the dog. To them, it is absolutely not friendly or cute. So maybe it really was vicious and the people that befriended it just thought it was nice.
A third says, "There wasn't a dog." Often reality is confirmed when other people agree that it is real. If nobody else noticed the dog except you, do you think you might question whether or not it was really there? Maybe it was a cat, or a child wearing furry clothing crawling on the floor, or an ottoman, or nothing at all.
Someone else says, "The dog doesn't exist anymore." We usually assume that when something such as a dog leaves, it is still real somewhere else. We have learned from past experiences that it probably still exists and could come back. But for all we know, it could be gone forever. In this case, the dog continuing to exist after it leaves the room is merely the result of a preconceived notion, or what we think to be real.
All of these people are right about the dog's reality because it is what is real to them. So maybe real is just what we think is real. If this is the case, then what is actually real doesn't matter at all, and what really matters is what we think is real.
How can we learn from this and apply it to our lives? Even if you really care about someone, if she doesn't think you do then to her your care is not real. We need to show people how we really feel or else they might not know. So do something nice for the people you care about so that they know it too.
"...How do you define real? If you're talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain." --The Matrix