Imagine this scenario: you have been living your entire life shackled to an imaginary story of who you are. Your story tells you that you're this way and that way, with a fixed personality. And you believe so strongly that this story defines you, but in truth it has nothing whatsoever to do with reality -- it's simply a fanciful construct of the mind.
... for most of us this isn't just a wacky scenario, it's our everyday reality! And because of our constricted inner stories, we live lives of perpetual suffering.