“Keep in mind that one of the mitzvos is to understand the real world, i.e., the physical environment, human behavior, and the effects of human behavior, inter alia”
Which one of the taryag mitzvos is this? I suppose Rav Yisroel Chaim Kaplan, Mashgiach of beis medrash elyon and a lamed vavnik, did not fulfill this mitzvah, as his rebbetzin had to remind him the difference between a nickel and a dime every time he used them! A lot of gedolei yisroel, especially in later generations, were aloof from the world and did not know “velt zachin”. That did not diminish their daas torah and their understanding of how the world runs on a deeper level. The heiliger Steipler was as cloistered in learning as can be, yet he had a profound understanding of psychology, as can be seen in the seder aitzos vehasrachos. He could have easily been a top notch therapist if he had so chosen, without reading one psychology book.