Life tip for you. Life is not black and white. It's full of many, many shades of grey. If you go in with an attitude of 'This is what I think, I'm going to state it as fact and refuse to listen to anybody with a different opinion', you will find many situations like this, where people challenge you on what you have stated as 'fact' when others with a view from a different angle can see another side or perspective. Don't shut yourself off from debate, but learn to engage with it in a healthy manner. Listen to other people's perspectives and gently present your own. Also, if you don't want people disagreeing with things you've said, not only will life be difficult, but a forum probably isn't the best place for you to spend your free time!