Solipsism

Solipsism is a philosophical theory that the human mind can’t be sure of the existence of anything but itself. In other words, all experience is subjective and only the self is real.

This view is generally regarded as egocentric, skeptical, and illogical, but solipsism raises important questions about the uniqueness of one’s experiences and mental states. For example, when I feel pain, how is it similar to or different from your sensation of pain? Can we ever really understand or know what is going on inside someone else’s head?