Is there a contrast between the truth of our lives and the story we tell of our existence?

“From this point forth, we shall be leaving the firm foundation of fact and journeying together through the murky marshes of memory into thickets of wildest guesswork”
J.K. Rowling's Dumbledore, Harry Potter and the Half-Blood Prince

Yes, and No.
Perhaps every story we tell has some form of truth in it of our own lives, whether fiction or not. Perhaps we cannot escape from this.
This is all dependent of course, upon the extent to which our writing is self-conscious of said truth-telling. Perhaps the story we tell is the truth of our lives because we believe it to be true. Memories are vague and adapted; the human mind is unreliable and distorts what we cannot remember. If, however, we know we are editing and adapting the facts of our lives for whatever reason (to be entertaining, to be original, to avoid displaying emotions and experiences we would rather forget..) then there is likely to be a contrast between what is true and what we tell.
A wise woman once said that her writing life was 'the inability to distinguish between the real and the imagined, or rather the attitude that what we consider real is also imagined.' So although there are many differences between our experience, our memory, our testimony and the final document, eventually what is true and what is imagined combine to make our work our own.
Perhaps we are unable to separate the two, whether we like it or not.

The wise woman was, of course, Margaret Attwood, but Albus Dumbledore is pretty cool too.

Is the writer, as an artist, special and if so, how?

'As a trafficker in climaxes and thrills and characterization and wonderful dialogue and suspense and confrontations, I had outlined the Dresden story many times. The best outline I ever made, or anyway the prettiest one, was on the back of a roll of wallpaper.'
Kurt Vonnegut, Slaughterhouse 5.

Naturally, there is a copious amount of esteemed and inspirational critics that may attempt to explain why a writer is special. Perhaps the fact that most people at some point in their life want to record their emotions and experiences, however some do not attempt this, no matter how much they desire to do so. Perhaps we all wish to write in order to leave a mark of our own on the planet that we would otherwise be unable to accomplish through any outrageous or dangerous achievement, and yet would be remembered for. A writer is special through the way that they write, and the fact that they write and express themselves through writing in the first place. Nevertheless, it is evermore difficult to begin to explain how a writer is special.
The term writer itself appears to be an impossibly vast notion. There are travel writers, novelists, biographers and the like, but there are also writers of video game scripts, catalogues, greeting cards or sermons. Are they just as special, important and artistic as a billionaire who made their fortune through a collection of best-selling romance novels? I find the most fascinating writers to be those who are wonderful but barely established, similarly the anonymous writers, and mostly the writers who want to achieve something within their work that is so significant that one can barely believe they have been able to record something of such magnificence. The reason for this is almost irrelevant in this case, but how they do it, and the way they do it, is possibly the most inspiring attribute of a writer. A writer is special if they can form the connection with the reader, whether the reader is expecting the connection or not. As an art form, literature and writing is arguably just as unlimited and expressive as paintings or sculptures, therefore a writer is special because they can reach no boundaries with a reader's anticipation.
I have most recently read Kurt Vonnegut's Slaughterhouse 5, and to my surprise I have found my new favourite novel. Perhaps not my new favourite novel of all-time, I do think I am still waiting to discover that particular item, but a book that all the adjectives in the world could not describe the profound satisfaction I felt at the turn of the last page, and the inspiring nature of the author himself, despite his adamant remarks that the book really 'is a failure', (part of his charm, I believe). But is a book ever a failure entirely? A writer is special, just like an artist is, because it is unlikely that any piece is admonished by everyone; the most offensive of writing could be appreciated by someone, even if it is the author themselves, however bonkers they truly are.