One of the things I always find fascinating is the amount of willful ignorance that goes into our industrialized food system. It's not that we don't know what's in our food, it's that we purposefully don't ask. I have to make myself not think about what I know about the conditions farm animals are raised in to be able to eat dinner.
My husband was surprised the other day when I mentioned that fast food hamburgers don't come from beef cattle. They come from dairy cattle that's stopped producing milk. I don't know why this horrified him so, but it did. It started a conversation about practices in the meat industry that are even worse, such as feeding the cows ground up bone meal from other cows, de-beaking chickens so they don't peak each other to death in crowded cages, etc. The horrors go on, but I won't.