My confidence is pretty good until I know exactly what I'm getting into. Then sometimes I go "oh shit." The initial idea seems brilliant, then the actualization is intimidating until I cut it into realizable pieces.
I'm usually pretty confident about getting things done on time, not so much if I have to think up something new to go with it, unless I already have an idea of what I want to do, even if my imagination is pretty fertile. I guess I tend to think of stuff coming out of my brain as stuff I can't force, and I want an easy way out just in case I can't come up with something.
Other things... I guess, unless it's in writing, I'm not very confident in my ability to say the right things.
I feel lazy no matter how much work I do but I'm usually pretty confident about when I've found 'enough'.