The "God nudges" are those unctions or impressions in our spirit that come from God to do something he's desiring of us. It could be saying a prayer for a friend you haven't heard from in a while, or giving a monetary donation to a family in need, or listening to a particular sermon that catches your attention. These are moments in time where God is gently "nudging" you to do something that will ultimately be for your benefit and his glory. It's always awesome to follow the God nudges because you never know where you'll end up, but it'll always improve your life and be an amazing adventure.