Solipsism (pronounced "soll ipps is-um") is the philosophical theory that only one's own mind is the sure existence. As an epistemological position, it is the concept that nothing but one's own mind can be "certain" to exist. The existence of other minds, in this position, is considered a possibility, but not a certainty. Including time, which does not stop just because there would be nobody being to experience it (which is probably going to happen in the end of the universe when there would be simply nothing)