A lot of people talk about being "who you are" in a positive way, as if it
were a good thing. This stems from a lack of consideration over who humans
really are. These people have apparently never stopped to think about base
human nature.
  What is the nature of the human? Is it good? Is doing good things natural
to us, or do we have to try hard?
  In its natural state, a human being is a lazy, selfish slob. Nobody really
likes to do work. It's not what comes naturally. If we didn't try to do
anything, we'd just sit around all day, eating whatever came within reach,
thinking about food and sex. This is who you are. It is what you will be if
you follow your natural impulses.
  People speak often of being "civilized". What does it mean? Doesn't it
basically mean being well-groomed, well-dressed, and well-behaved? Indeed.
Yet this is not what people are; It must be forced. You're not naturally
civilized. You have to try to be, if it's what you want to be. Isn't the idea
of civilization all about suppression of basic instinct, of being something
you're not? It is.
  By extension, what is life but suppression of your bestial tendencies? A
life of laziness and thoughtlessness is pointless. There is no meaning or joy
in it. To be anything or have anything in life means to put effort into it.
Almost anything worth having requires you to be something you're not.
  Take physical health as a fairly obvious example. Who are you? Are you
someone who likes to eat bean sprouts and asparagus? Probably not. You're
more likely to be someone who prefers unhealthy foods, like lots of red meat
or donuts. But you know that you'll regret it later on if you eat nothing but
donuts all day, so you try to eat foods which are healthier. You know that if
you give in to your impulses, you're only hurting yourself.
  What is my point in all this? Simply that "who you are" has little bearing
on what a person is or should be. Humans have a remarkable ability to decide
and shape their personality and behaviour, beyond that of any other species
on this planet. There are not many behavioural conditions which cannot be
corrected by the human who exhibits them. People unable to change their own
actions suffer from a lack of self-awareness or self-control. They cannot use
"this is who I am" as an excuse.