Or that you are a space alien, and that Thetans fill my body. Sorry, you're babbling now.
One of the soundest arguments of philosophy (faith and belief) by Descartes for reason by doubt. That only you exist and that everything around you is created by your own thought for your own benefit. Solipsism is hard to refute by philosophical argument because one can deny anything. Science does not even address it because it has not been observed as fact. However the church denied and renounced Descartes's proof by argument. The soundest argument against Solipsism is that most who believe it are considered insane and reside in a insane asylum.