and why would he tell you of all people this tidbit of info?that might also explains why at times you see him go threw progressions when reading defenses.
You do realize that going through your progressions and reading defenses are two completely different things.
Reading the defense is recognizing what the defense is doing before the snap. Seeing the coverage scheme...seeing where the blitz is coming...understanding what the defense is trying to do based on formations and movements.
Going through your progressions is quickly moving to your second, third, and fourth options if the previous ones are not open.
Not even close to the same things.