I never said it was a matter of opinion. It's objectively true or false. But that doesn't necessarily impact one's thought process on the subject. A matter of opinion and a matter of objective reality can both be processed in the same manner intellectually (whether they should or not). So when referring to one's thoughts themselves (the "opinion"), it's beside the point to consider whether the thoughts pertain to something that is subjective or objective. The mental actions are the same.
I am not persuaded that that is so.
An objective concept is held as a whole. We know this because if we think of, say, the wording of the Fifth Amendment, we know if we have it correct or not.
If, however, we try to explain a subjective concept, we have no such difficulty. We may gloss over contradictions, invent examples, hedge around parts and be vague or emphatic in others. None of this would help us if the concept were objective.
In subjectivity, our thoughts go to the defence of our position and the impact the statement will make.
In objectivity, our thoughts go to accurate recall.
The only similarity I can see, off hand, is that in both we may be aware of inaccuracy.
Some people are of the opinion that Obama is a Kenyan-born Communist. They are objectively wrong. So how do you classify their belief? I'd call it a position, a conclusion, and an opinion.
“delusion” [dih-loo-zhuhn] (noun) = the incorrect assessment of a correct perception; a belief held in the face of evidence to the contrary, that is resistant to all reason.
They have managed to hear both for and against but feel compelled to misinterpret. See how similar this is to subjectivity?