Self-confidence vs over-confidence

According to this post here, with my score of 7 out of 10, which puts me at the upper end of the norm. People usually score 4 to 7, with 1 being a lack of confidence, and 10 being the uber egoistic.

Self-confidence comes when you know yourself, know your limits, know what you know and what your don't know.

Over-confidence comes when you don't know yourself, think too highly of yourself (not being realistic), don't know your limits, don't know what you don't know.

It is easy to slip from self-confidence to over-confidence. The key to preventing that from happening is to be self-aware. But you must also realise that self-confidence is not a bad thing. We need to believe in ourselves, otherwise we will lose hope. Self-confidence earns you the trust of others (who would believe in a guy who wouldn't believe in himself?) and prevents worries (which clouds your thinking) from getting in the way of execution.

So some confidence is good, but not too much of it. The key is to learn more about yourself.