An excellent point. I seem to have forgotten the problems I had overcoming parallax issues. They can very much account for a 1" flyer at 50 yards. I guess I don't think much about it now because all my scopes have AO adjustment. And I set it for the distance I'm shooting too. And again it takes practice to get it set right quickly. The numbers the paint on the scope are just approximations of what you will see in reality. With your AO set correctly you should be able to move your head around without the crosshairs leaving the target. If it isn't set correctly you will see the crosshairs move off target as you move your head and that means you better be lined up exactly or your shot is going to miss your target. I used to work real hard on having a consistent hold on my rifle but an AO adjustment works better and is easier to deal with.
It takes a while to learn all these things. I suggest you don't give up. Just practice and learn.
