Nobody's perfect. It's not like I'm 100% correct 100% of the time. Perfection is an ideology and an illusion. I can't be right all of the time, because that would make me perfect, which is IMPOSSIBLE for ANYBODY. My opinion can be wrong because I might not know everything about the situation, or I'm biased, or even maybe I haven't formed an opinion at all, which would technically be "wrong", right? So I am PERFECTly capable of being WRONG.
Facts are things that can be proven one way or another. They have a clear right and wrong answer to them. Opinions, On the other hand, Are thoughts that vary between individuals and thus have no basis for being right or wrong. Many times different opinions can be influenced by the same facts (For example, Sue likes Pepsi because it's sweeter than Coke, But Adam prefers Coke because he thinks Pepsi is too sweet), But that doesn't make one opinion less correct than another. What makes matters difficult is when people confound facts with opinions, Or when they confound opinions with beliefs. Beliefs can be disproven, Like during criminal investigations, But opinions cannot be wrong by definition.
I think that every opinion is stricktly related to someone's experienced, studies, how h/she has lived since that moment and so on. At the same time, it means that your opinion can't be wrong for the same reasons. Thus, talking about the exactness or wrongness of someone's opinion is totally useless because they're limited to that someone's background.