describe another instance that brings Winston back to reality and realize his desire to overthrow the Party? Be sure to describe what brings him to this mindset?

I think the moment that O'Brien loans Winston a copy of the Eleventh Edition of the Newspeak dictionary is pivotal. Winston actually begins to believe that O'Brien might be part of the "brotherhood". Winston's rational side thinks this idea is still "folly", but his emotions for hope get the best of him.