All self expression is a lie.
A lie of omission.
Interesting mental structures (maybe all mental structures) are too complex to be accurately expressed through any medium. Any expression is therefore unfaithful in some important way to the throughts and feelings that engendered it.
Which is not to say that creativity and expression are useless or uninteresting; just that all communication is necessarily incomplete, which is incredibly frustrating. You can slave away on whatever is it you're working on, you can devote your life to your chosen artistic medium, and no one will ever feel just what you're feeling or think just what you're thinking. Despite the increasingly connected nature of our society, regardless of the number or closeness of the relationships you have, we're all still marooned on our little islands by ourselves, sending smoke signals to each other over the water.
I hate that.