What is the obsession with not mixing Chametz with Matzo about?....?
on pover we do not eat leaven/chametz or use ovens, pots etc that were used with chametz. the torah text tells us to make sure that not a single bit is found so we pour ourselves into the task of cleaning so that we can be sure we celebrate the pover with the law having been followed as best as we can. is this "obsession"? call it what you will -- we see it as dedication to the laws of judaism.