"Immune"

I'm immune to the world
And I think that's bad
We're all going to die
And I don't seem to care
There must be something wrong with me
But I don't see what it could be
I'm just pretty sure
That if everyone is running and screaming
I should be reacting the same way
But I'm not sure why everyone's scared
I'm immune to the world
Will someone please tell me
What is so bad?