Some people who think they are writers are delusional.
Sure those of us who write with the goal of being published (and maybe even earning a living at it) are all delusional in a way, but it's not a bad sort of delusional. It's more of a dreaming (with lots of hard work thrown in.) Writers are delusional in a similar way to those who want to be professional musicians or actors. It's a long-shot, but you can actually work hard and hone your craft until you get some breaks.
The short and skinny is that a person who writes, does so because they must. Nothing anyone else can say could persuade a writer not to write. The desire to create with words is a compelling force that they can't deny. It is part of their dreaming self, this need to write which makes them a writer. Getting published is a whole other ball'o'wax.
But there are also those wanna-be writers who are BAD DELUSIONAL. Run from them.
Bad delusional is the guy at the back of the bus who smells like incontinent cats and mutters about being an archangel. Bad delusional is playing slot machines as part of your investment portfolio. Bad delusional is quitting your day job before you even start your first novel because "Hey, I'll get a Stephanie Meyer deal right out the gate."
I once met a guy who claimed to be a writer. I asked him what he wrote.
"Oh, I haven't written anything yet."
Really? Well, if you were to write something, what genre or style would it be?
"Oh, I'm only going to write best-sellers. Or soemthing that would ensure my literary fame. I won't waste my time writing anything else."
And during twenty hubris-laden minutes he proceeded to tell me how terrible every best-seller was, how his would be superior and that he was studying what was hot right now and would just follow the formula of best-sellers to write his guaranteed hit novel. And yes, he told me how publishers would be throwing money at his feet when he told them he was about to write their next block buster.
I never knew people like this existed.
And if you haven't yet seen this video, stop, turn off the music, shut the door, press play and put down the beverage to avoid soaking something.