opinions are like....

I've noticed recently, either because this is new or because I am now old enough to recognize it, that people try way too hard to change the opinions of others. I understand it in the case of an opinion that is of a dangerous nature (racism and the like) but honestly, if it is of my opinion that, say, ketchup is disgusting and you're threatening my life because of it... you have problems. You'd think (or at least I would) that since we've been in existence for two thousand and almost twelve years, someone would have realized by now that we are all different and therefore do not all think the same way. And isn't that the point of being alive? I'm all for a debate, usually, but why has it reached a point where everything has to be debated. Can things not just be left alone? My opinion will not change your life and the same goes for yours to mine.