One such profession would be a waitress. Now, I'm most definitely NOT claiming to have been a fabulous waitress, previously in my life, yet I can recognize the need to own what you are selling/serving. On my recent trip back to the D (metro Detroit area really), I went to check out 'South' a new, LA/poshy restaurant, bar in downtown Birmingham. I'll give them the fact that they just opened, but the waitress was so unconfident it was awkward. First with the Michelada... which was exciting to see on a menu in Birmingham. For those of you who haven't had the pleasure, a Michelada is a kind of bloody mary beer drink from the latin lands. The waitress pronounced it Mi-kela... lines the rim with sugar (not salt) and then asked if it tasted good after she served it. She then proceeded to ask us how the rest of our food and beverages were because she 'hasn't had them and always wondered, I mean they look good but she just didn't know'. I mean come on, at one point she was interrupting our conversation, a long awaited international catchup session.
Another profession that should really add confidence to it's needed skills is a yoga instructor. I know that yoga is for everyone and that it is about much more than just the asnas, yet the person leading the group must go confidently and with direction through the class. A recent class, with a rather new teacher brought this to my attention when I found myself thinking I'd rather be doing yoga alone.
Of course it's always easy to criticize. I know that I frequently lack confidence, living in a world where I am a bit of a fish out of water. But I will continue making speculations from my view here on the beach.