Mistakes can be mistakes of which allow a contract to be voided or mistakes of which do not.

For a mistake to discredit an agreement, it typically should be a shared one about a material actuality or fact. Rarely a one-sided mistake will discredit an agreement.

well it depends i think people around the world are coming around to gay marriage. but if you are talking abortion then wow, so much to talk about. such as men thinking they have the right to choose if women can, the fact there are health concerns if the women can't get one, and many more arguments to discuss. so i would definitely say abortion would be a much more interesting topic.