There was me thinking (was: ceneme (n.) -- plereme (n.))

On Mon, 25 Mar 2024, Janet wrote:

  There was me thinking the bible was written down long
before King James could hold a pen.

Am I right to take "There was me thinking ..." as an idiomatic mocking way
of saying "I am sure that ..., so you must be wrong." If so, I'll try to
remember it. As a non-native speaker, I am always looking for such phrases
to remember.

{If someone is interested: In German you would say
"Und ich dachte immer ..." (lit.: "And I always thought ...")
in such a situation. The "und" marks a contrast, perhaps in English better
rendered as "but" or "well,".}

--
Helmut Richter