Put this in the category of "candidates say the darndest things".
Candidate: "I've been doing performance tests; I haven't actually gotten to write tests in a long time and I really want to. I want to look at emerging technologies and get into writing tests and test harnesses, not just running tests."
Me: "So what have you been doing to prepare yourself for such large transition?"
Candidate: "Um.... well... I write code every day, just not writing tests.
I think I'm already prepared."
From the same candidate:
Me: "How would you characterize your expertise at Perl?"
Candidate: "Oh, I'm very good at it. You can ask me anything."
Me: "Okay, tell me what the major difference is for you between object-oriented Perl and standard Perl."
Candidate: "Oh! Object-oriented perl is just Python. It's really just a change in how you set up in your GUI environment."
Confidence is great. I'm a huge fan of confidence. But if you're going to be confident, please be correct!