Here's today's Dilbert cartoon.
It's the combination of Ratbert-like insecurity and self doubt, and amazement at the self confidence of people "out there". Knowledge isn't wisdom, after all.
Incidentally, if you want a feel-good story read Scott Adams' account of recovering his voice.
On the other hand, don't. There is no point in me (with my 30 hits per day) encouraging you to read his blog (with its number of hits on the other side of 1000 times that amount per day). *Sigh*