I think everyone prepares for it differently - personally I had no interest in watching the video of a woman giving birth as I felt it would only reduce my confidence and not offer any real insight into what the birth would feel like. Speaking to other women who'd had natural births (especially my mum who had 3 kids with minimal intervention and my grandma who had 8, about 5 of them at home with no medical intervention) helped my confidence a lot more. And for me, it was not so much "how much I wanted it" as "how much I believed in my ability to do it". IYKWIM!