I suspect those beliefs we have influence our lives the most in cases of ‘I am’ and ‘I am not’ that are, like you say, usually accidental rather then factual. Aka “I am an introvert” or “I am bad at mathematics” becomes self fulfilling prophecies.

What you tell here is not new to me but its also does not seem to be widely known or accepted view on human reasoning abilities.
And this view causes many questions. Aka if we are so delusional about reality we live in how did we got where we are? Is environment not that harsh and allows us to be delusional about it? How did we survive as a society that holds delusional opinions?
I heard that objective view of reality may not be necessary to thrive in it. We did not evolve one for whatever a reason. May be even to an extent of objective view being counterproductive to our early survival. But there should be at least a degree of understanding part of reality that meters…

But all in all good pointers in terms of understanding and respecting others and being humble over our own, usually, delusional views.