I teach Geometry this year and it is a VERY rigorous math topic. It requires such logical thinking and processes that students generally do not encounter every day. We have ALL learned to "short-cut" our way through so many things and Geometry does not allow for short cuts. It is also requires you to defend yourself which is rigorous in and of itself. Students don't like to be asked "why did you do it that way?". I have finished Chapter 1 and am almost through with Chapter 2. I am looking forward to finding new ways to integrate the rigor of my subject area in ways that the students do NOT dread it :)