Human Nature is a fact not opinion.
This is the kind of statement that keeps getting you in trouble and you keep failing to understand why.
Read what you said: Human Nature is a fact not opinion.
Now, kindly explain (with some evidence as you will see demonstrated below) exactly how that is true. "Human nature" is an abstract, an idea, a phrase made up (ironically, by humans) to describe any number of different things, depending on who is speaking and in what context. You just throw these terms out with no frame of reference whatsoever, then you get defensive when someone calls you on it. Your language use is ...mushy. Vague. Unclear. Without appropriate context within the bigger conversation. Abstract even to you, by all appearances.
That does not in any way fit the definition of the word fact, which is:
fact [fakt] noun
1. something that actually exists; reality; truth: Your fears have no basis in fact.
2. something known to exist or to have happened: Space travel is now a fact.
3. a truth known by actual experience or observation; something known to be true: Scientists gather facts about plant growth.
4. something said to be true or supposed to have happened: The facts given by the witness are highly questionable. (Before you get mad, let me state that I did a cut and paste from http://dictionary.reference.com/browse/fact . The coincidental applicability of the italicized words is a coincidence. Don't read anything into them, it's just what the site stated.)
mean by human nature is not necessarily what anyone else
means by those exact same words. If you insist on speaking in abstract terms with no accompanying support for your specific application of them, you're simply going to keep having the same endless circular conversations you've been having so far. Figure out how to say EXACTLY WHAT YOU MEAN WITHOUT RELYING ON VAGUE GENERALITIES and these conversations may actually be worth pursuing with you.
Or keep doing this, and keep being proven wrong. They're your 24 daily hours, you can spend them however you choose.