I'm in the middle of a pretty rough downswing (-$16.8k and running 17.5k under EV over my last 95k hands) and they say that adversity is the best teacher.  So I'm going to use this thread to post quick thoughts (and occasionally in depth ones) that I've learned or considered during my play.  Hopefully after I get out of my downswing these lessons will stick and help me avoid a similar one in the future.