I don't. But by not existing I must exist- in the Least existential manner, by speaking to you I prove that I, in fact exist. By conceptualizing whether or not I exist, I have proven through the dislocation of self that at least in a conceptual way, I do indeed exist. Unfortunately, my friend, having read this post has further verified my existence. Because had I not existed this very post would not have been made, nor would you have read it. In a basic manner, I exist because I choose to, and am verified in my existence by your existence.