Why? What is it that I need to change?

Reality has also hit me when it comes to exercise today.  I have no real desire to lose weight.  I went to the doctor Wednesday and she stressed or rather recommended exercise.  I have not been exercising lately because something is wrong with me.  I had this issue before despite my health issues and everything associated with losing weight.  The truth is, despite the fact that I have every reason that I need to exercise.  I have no desire to do so.  I realize that I am not doing something right.  What is really wrong with me?