Overconfidence is a state of mind which is too sure of itself. The term is a negative in common usage, referring to an unrealistic perception or concept of a situation or possibilities. The sarcastic version of overconfidence is a belittling expression referring to someone who lacks confidence to an extreme. The usual context of overconfidence refers to a mistake of some kind.
Examples of Overconfidence:
I'd say that your overconfidence was obvious, trying to arm wrestle a gorilla while drunk.
Certainly can't be accused of overconfidence, can you? Most people would be fairly sure they could click a mouse without a chaperone.http://www.cbdr.cmu.edu/papers/pdfs/cdr_576.pdf