Solipsism is the realisation that you have no proof that anything actually exists other than your own mind. “I think, therefore I am” All of your senses and perceptions are actually signals on the I/O surface of your mind, you can’t prove you actually have eyes, only the perception that you have eyes. Ancient Greek philosophers first discussed this and later Descartes and Hobbes developed the ideas. Nowadays solipsism is a powerful character mode that you can assume for doing things such as public speaking, competitive sports, or special forces operations. Train your mind to be able to enter an alternate belief system where nothing actually exists other than you, from this state you can do unusually difficult things with supreme confidence and determination.