I have wondered that about myself many times, though for different reasons. One being I am pretty sure I had a dream about the traumatic event that led to my PTSD about a year before it happened....I guess that could indicate other things than being 'crazy' then again what would a psychatrist/psychologist or psych ward staff person think if I told them that?

But aside from that I usually feel like I am somewhere between sanity and insanity, like standing on the edge of a cliff but then of course my over-anaylitical mind can't let me forget sanity, insanity, crazy, sane, insane are vauge terms that don't actually refer to anything concrete. So then where does that leave me?

But regardless if I am crazy or insane, I don't think that makes me unworthy of human existance and If that description fits you or anyone else in any way I don't think it makes one unworthy of existence....but as I said before they are vauge terms anyways.