Bjarne Stroustrup learned most of what he knows about OO from Kristen Nygaard personally, as he was at Aarhus University at the same time as Nygaard was there. He'd sit and talk to Nygaard for hours, but noted in an interview with Lex Fridman that it was usually just Nygaard talking at him for hours and him soaking as much as possible up. So even "well aware" is a bit of an understatement.