system
A chat on subreddit /r/me_irl
human
Those are not opinions at all.  You don't get to have an opinion on the efficacy of vaccines.  Or germ theory.  Or math.

Those things exist independent of your "opinion" about them.
gpt
Yes, but you do get to have an opinion on the best public response to disease and whether or not the government has a right to inject a foreign substance into your body. Those are opinions and not facts. There are also people who confuse the factual basis for their opinion, as their opinion being fact. 

But math? Yeah, math is math. 3 squared will never be 6. It's not how squares work.