Prove your own existence.

Everyone knows about the theory that you cannot prove that another person exists, only that they are created by another level of consciousness, or your imagination. I do believe that this is a possibility, but I am taking it a step further. Prove to me that you exist. Now prove to yourself that you exist, bearing in mind that any "stimulus" of the physical senses could be artificially evoked by your subconscious, including the sense of sight.