Strong Arm Out of Commission
I have been training and teaching for some time now and always teach about having your primary arm put out of commission. I can tell you that unless you have experienced it first hand, there is no comparison.
I just had extensive surgery on my right arm and it is out of commission for about 6 weeks before I can even think of drawing from a holster. While I trained to use my off hand, I realized I was pretending. Nothing like the real thing to wake up the need to be ready. I can only imagine what it would be like had I not been working on it.