I'm pretty much on par with ashepp33 - I have an irrational fear of dying, and/or the world ending. And so with all the uprising in the Middle East and the disaster in Japan, only a few short years after the devastating earthquake in Haiti, how can you not start to think that? And I'm sure there are people out there who shrug it off, and others who think about that too, but I dwell on it.
I lost my license for a year, lost my job subsequently after just being in my first semester in college, I started having panic attacks.
I guess the root of mine is generally speaking, religion. I know the world will end some day (the Bible tells me so) and I doubt my faith in God, and if I do that - will I even get into heaven?
The rest kind of follows...
Until I started CBT I never thought that religion was the cause. But after a few months of closely monitoring my anxious thoughts, where and why they happen, I think I finally figured it out.
And to answer Vincenza's question, why it helps me to understand it, is now I know what the "root" is, I can start to figure that out, hit the nail on the head so to speak. And it's important to me to be able to free myself from these panicky thoughts.