@crossproduct: Who are "they"? Who are you talking about? I haven't addressed anyone specific so I'm not sure what you mean. I'm asking why the people who are delusional, are delusional.
Let me break my question down for you so you understand it...
1. There are lots of delusional people in the world. Whatever definition you use, that is true.
2. I want to know why are so many delusional people are delusional?
So I'm asking "why" there are so many people that are delusional. I'm really confused as to what you don't understand, it couldn't be simpler.
I do not claim to know about pyschosis or delusions and never have. In order to understand the core elements of something, like understanding the meaning of a word, the simplest thing is to google the definition so you at least end up in the right ball park. If I was being lazy I'd have just said "mad" or "nutty" people. But because I think that would be rude and disrespectful to the people with the illness itself, I bothered to make the effort to use the word delusional, once I'd checked its meaning. I included the dictionary definition so that anyone reading the question would know exactly who I was referring to in the question.
And at the end of the post, using that same dictionary definition, I'm asking whether there is a large group of people whose behaviours would mean they all fall in to the category or under the heading of delusional.
Understanding the definition as intimately as you clearly do, it sounds like your answer to my question should have simply been "I do not think there are any large groups of people who are all delusional because the dictionary defintion you have used isn't accurate enough for me personally." And that would be fine. I'm afraid we can't all experience something or eductae ourselves wholely about one specific word before asking a question about it, that would be unrealistic.