My worst hallucination was when I thought people were breaking into the house I was living in at the time. For me at least there was absolutely no difference between the people I was seeing who weren't there and the police I called because I thought people were breaking in. Eventually the police ended up essentially walking me around my house proving to me there was no one there and even then I was still "making up" lamer and lamer pieces of evidence for the break in in my mind.

I told them several times I wasn't hallucinating and I think they were pretty freaked out about the whole thing until they found my meds and realised I wasn't high or abusing some other drugs.

Retrospectively it's pretty easy to see the point where I started seeing things but at the time (at least for me) it was a really slow and insidious process.

I read the article but luckily for me I was never really delusional for very long at all, aside from a couple of incidents like the one above I wasn't really hit by the hallucination/delusional side of schizophrenia so I'm not really qualified to talk about what it's like but I've read before that (sort of like bipolar patients) a lot of schizophrenia patients simply refuse to believe anything's wrong at all, which is one of the big challenges when trying to gain medication compliance.