Today I met an actual flat earther

[sabbat hunter]

119. my grandfather

escaped Poland around 1917, went to Italy, then to Argentina before coming to the US

But despite all of that he was a very learned man in the Torah and Talmud. After he retired he would study the Talmud every day (except saturday),sometimes twice a day. (right up until he was about 91 he did this). He would also lead his synagogue in the services when the rabbi was away or sick. Some in his Synagogue even called him Rabbi Jack.
He knew that the earth was not literally created in 6 days. He knew that most of what was in the bible was stories, on how to lead our lives, not to be taken literally. It is why he found the Talmud so important, because it was the study of what the words in the Torah actually mean.

He studied the Talmud up until he realized that he could not keep up with some of the younger people studying along side of him of what they were discussing. (the people he was studying along side were up to 70 years younger than him when he stopped!)

But with all of that, he did not finish HS.

You do not need a formal education to realize that the bible is not meant to be taken literally. It is not a lack of formal education, but a lack of WANTING to know more that is the problem with the "6 dayers".