Right and wrong way to use it

Not all of us have enjoyed 'self confidence'.  It can be plentiful  or sadly rare.  Mine comes with how I use my hands to fix, improve or beautify different things.  That I believe, is where my brains are.  Now give a calculator to me and ask me to add 12 and 14 and I'd be in trouble.  But let's get to the real problem, that of those who perhaps unwittingly flaunt their areas of self confidence.  They seem to be experts just about anytime they open their mouths.  I probably could learn something from them (or not) but it does get boring listening.  Sadly, I believe they have no idea how they sound or even act.  Its just them being them.  I on the other hand (or both) :), can with great self confidence frequently be heard to say "I don't know" with no qualms or feelings of shame.  But when I don't have to say, "I don't know", oh what a high!  It does happen.  I remember just last month..............................marge