Your friends will believe in your potential, your enemies will make you live up to it.
Have you noticed how difficult it is just to get along in the world? If you're no good at all in your job, people treat you badly and eventually you will be unemployed. And if you're a little better than competent, everyone expects miracles from you, every single time. Like most of life, it's a no-win situation. And if you dare to mention it, no matter how creatively you phrase your complaints, you are shunned as a whiner.
A good manager instills staff with self-confidence, teaches them to believe in themselves and helps them to realise their brilliance. Do not ever treat your staff with disrespect. It is competent until proven incompetent; not incompetent til proven competent.