Originally Posted by
rob_s
Why are you so resistant to the idea that you may be wrong?...
Just because you believe a thing to be so, and have believed a thing to be so for however long you have believed it, does not make it so. Nor does pointing out that large groups of people share your ignorance. All of Europe once believed the earth was flat.
Understanding the difference between initial intersection and zero matters. Spend some time on the range wig a group of shooters at various distances and you will start to understand why.