On the contrary, you seem to be under a strange delusion.
Is it? Many people seem to disagree. But perhaps more to the point, your behavior indicates you disagree with yourself. You seem to claim that you know morality is subjective and that you know there is no such thing as objective morality. But, yet, despite claiming that you know that, you don't act like you believe it. If you really thought that morality was subjective, you'd treat questions like whether it was appropriate to murder your neighbor the same as questions like whether you prefer vanilla to chocolate.
Yes, but the vast majority of people that express their moral beliefs do think that they are objectively correct. That is to say that for example they do believe it is objectively wrong to murder your neighbor. Whether or not they can prove that to you or to someone else is irrelevant. They believe it to be objective fact of the same sort as 1+1=2 or that the sun revolves around the Earth, which they probably can't prove to everyone's satisfaction either. And that's why they would tell you not to murder your neighbor and judge you for doing so. But you are saying that in reality you don't think any of this morality stuff is objective fact, even your own opinions. So why do you bother to argue about it or care particularly about what others believe about it? They aren't necessarily acting incoherently, but you are.
All I'm saying is live what you believe. If you really believe mortality is subjective, then act like it. Merely believing that morality is objective but you can't prove your particular point of view, perhaps because you lack the skill or perhaps because your audience are idiots, is a different thing that suggesting it's subjective.