In the video how do you know you exist? It talks about how we exist and that what if you are a sleep and you are dreaming about everything that has ever happened to you. The video also talks about how you use your senses to see the world. And that only a crazy person can deny the fact that you really exist and the reality of life. This video relates to Sophie’s world because Sophie is taking a philosophy course in which she will have to answer hard questions like how do you know you exist and questions like this will make you wonder. One of the philosophers that Sophie is learning in her course does not believe in trusting your senses and another philosopher that she is learning about thought that your senses were lying to you and that you should never trust them you should only trust facts.