Your problem is in your form set up. You have invoice. Line_items.
Each_with_index do |line_item, index before your f. Simple_fields_for and you don't need it. Instead you should have...
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.