Are We All Self-Conscious?

No, not everyone is self-conscious, referring to insecurity. Most children from birth to about 9 or 10 wouldn't experience insecurities is imagine, even if they're bullied usually they'll listen to what their family has to say about them rather than what others their age has to say.

When considering the mentally disabled though it's hard to pinpoint a for sure answer. If I were mentally disable as portrayed by media, then I think I'd be a bit insecure about it, but that's only because I view it from my perspective, living in a place where you're blatantly different from a society that thrives on moderate assimilation. Yet when I talk to a "handicapped" person they seem happier than ever to be who they are and people are usually really supportive of them. Maybe I've missed something when analyzing this.

As for everyone else, yes we're all insecure. From a biblical pov, we we're made in God's image; he is perfect therefore it makes sense we would want to be perfect however that has never been achieved in the history of mankind except for one person. The only reason someone would be insecure is because they view something about themselves isn't perfect, therefore we are all insecure. From a secular stand-point, society claims perfection as having a lot of money and plenty of the opposite sex to mate with, yet even people who obtain that end up committing suicide, or if they try to go against status quo the they basically commit social suicide. Point being even what we view as perfect has flaws. Everyone is insecure..potentially excluding the two I listed first.