if you think about it, you'll realize that the only objective proof that you have of anyone's existance is you own. by all accounts of even the most modern research and theories, it is only through your mind, and your five sense, which you observe and experience the external world. since it is possible to stimulate the mind into seeing, hearing, smelling, tasting or feeling things that are "not really there", you can easily see that everthing that happens could be "self stimulated" and is happening only within your mind. 3d sunset