I Can Relate
Being a recovering drug addict myself, I can remember very clearly being way too messed up and thinking that I looked and acted fine and no one should notice. The more people would tell me or ask me if I was messed up the more I would deny it and become very angry at them for even thinking such a thing (well duh, why wouldnt they think it, it was true). I would deny it to the point that I would start to even believe it myself.
When you are in the midst of your addiction you cant possibly see how you are acting. It is once you get clean or sober that things become pretty clear to you. The saying about hindsight being 20/20 is dead on.
If Paula is using and is fortunate enough to ever make it to recovery, watching old video of herself will make her sick.