I disagree with this, as this is "false confidence." Correctness and humility go a lot further to true confidence, as being correct enables you to speak with authority on a subject (nobody is going to ask a follow up question that causes you to question your correctness and trips you up), and humility enables you an escape hatch to admit when you don't know (your audience will trust the things you correctly say even more, because you're not lying about everything).
Note that "correctness" isn't meant in an absolute sense--you can speak with confidence on something others consider morally abhorrent if you are 100% convinced of its correctness (which is potentially what you mean by "not being 100% correct"?).
First, it’s not a binary (true or false). Second, what I meant was that some people get so caught up in being 100.00% mathematically precise that they hesitate to even say anything. No one is saying not to be humble or as correct as possible. You can be more confident just by being aware that most people don’t know that much more than you in many cases.
Note that "correctness" isn't meant in an absolute sense--you can speak with confidence on something others consider morally abhorrent if you are 100% convinced of its correctness (which is potentially what you mean by "not being 100% correct"?).