Theory of Knowledge

We live our lives thinking we know a lot of stuff:it is 3pm, I have hands...But do we really know any of this? If a skeptic challenges us to prove that we are not living in a computer simulation, what could we say? How can we justify our beliefs? Can two people with the same evidence rationally disagree? We form beliefs spontaneously, but can we also sometimes control what we believe? Can we rationally believe something just because believing it will bring about good consequences? In what ways are we responsible for our beliefs? Can our practices of gaining and sharing knowledge bring about social injustice and if so, what can we do about it?