gzg, I agree with you mostly. I don't think you, or most of us, give ourselves enough credit for what we are capable of though. But, one must know one's limits and not exceed them, and I applaud you for doing just that.
I absolutely refuse to shoot a deer if I'm not 100% certain that I'm going to hit the lungs.
Nor will I. That's why everything would have to be good for me to do it. I'm not going to shoot at one that far in the woods. Too many things to jump up and hit my arrow. But if I'm hunting a field edge, there is not a terrible wind blowing and I am locked in.....I'm letting it fly. And I'm also certain I'm killing that deer.