A pretty good topic (pretty multi-faceted... ehem... is that the right word?
) ! Sometimes confidence in knowledge can lead one away from the truth ("never confuse science with truth").
There are so many factors influencing confidence... 'institutional' learning (which may or may not be correct), concept of self, punishments and rewards in the past, fear of being wrong, being exposed, being vulnerable, being less.
I like Bashar's thoughts on fear. Bashar says that fear of things doesn't stop you from doing anything... only the fear of being afraid stops you. This is part of what he has to say about fear:
How FEAR can Serve You (by bashar)
Fear means that you believe, that a scenario that you very much do not want to happen, is very likely to happen!
So fear lets you know that you are believing in a reality that you do not prefer. So, fear can serve you, by being an "indicator", or an "alarm", that lets you know that "Hey, I'm believing in a reality that is not at all aligned with my Being!"
Once you become aware of this, you can choose to change your belief, so such frightening scenarios will no longer pop up in your reality.
#1. Get in touch with the Belief that is causing this fear.
Ask yourself: "What would I have to believe, in order to end up being afraid of this right now?"
#2. Once you get in touch with the Belief that is generating this fear, then
Acknowledge that this is your current Believe. "Own" it. (You can not change what you do not own.)
#3. Ask yourself: "What Belief would I like to REPLACE this Belief with?"
#4. Once you decide what your new preferred Belief is, accept it. Adopt it. Breath it in. TRUST that this new Belief is now active and functioning in your Being. (You don't need to "get rid of" the old Belief. You only need to replace it with your preferred Belief.)
Get into the Mind-Set of the new Belief.
Get into the Emotional-Feeling State of the new Belief.
Get into the Body-Language and Actions of the new Belief.