Remarks on Belief
Cynical? They seem about right to me.
Another sentiment attribted to Mark Twain:
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." — Mark Twain
A similar idea attributed to Will Rogers. If so, probably derivative:
“It isn't what we don't know that gives us trouble. It's what we know that ain't so.” ― Will Rogers
I suspect that these saying have been around for a lot longer than these fellows.
"The humourist Mark Twain is often credited with a variation of this: “It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.” Ironically, despite the frequent attribution to Twain, we can't be sure who coined that pithy thought."
"What did Socrates mean by "I know nothing"? All I Know Is That I Know Nothing”: What Did Socrates Mean? Therefore, with the phrase “all I know is that I know nothing,” Socrates expressed that there is human (limited) and divine (limitless) wisdom. In addition, the philosopher believed that a person, the wisest of all after God, should not think they know what they do not know."
The older I get (at 80) the more I realise how little I know but I do know Jesus and that has saved me all my life - Psalm 91 - check it out :-) https://www.gatestoneinstitute.org/20532/words-of-light-in-dark-times