For me it's my ability to be viable in the near future.
I should be insecure about my singing voice.
I am not.
I'm insecure about the effects my personal knowledge has when dealing with others. As it turns out, the more you know the less people will be able relate to you in general. For instance if you know that religion is the same thing as witchcraft or any other mythical fantasy you will no longer be able to relate to the religious like you did when you didn't know. Knowledge is not only power; it's a separator too and it cuts like the sharpest of knives. In todays world knowledgeable people are looked down upon as know it alls who know nothing by the less knowledgeable especially if they are religious. My lifelong thirst for knowledge has killed my social life because I don't have the ignorance I need to relate to what seems to be the majority's level of understanding. If half of my brain died and I became a happy idiot I would probably have a lot more friends. And now as a country, America, under it's current leadership, celebrates ignorance not knowledge. So now I'm insecure about the whole dang country (insert nervous laugh and a sigh). With a vacuum of knowledge in the top leadership there is only one direction we can go and it's down and out and into war over nothing but stirred up emotions and misunderstandings.
@AmiSue well put
THe future of this planet...it don't look good.