How many People know and are aware that 2 knights and a king v lone king is drawn and know why!!?

Yes indeed ridiculous as it may appear but if you know the process you can draw with a lone king against a king and 2 knights!? I was present at a weekend chess congress Major section and was watching along with a big crowed a game where one guy had a single lone king v a king and 2 knights! the lone king had headed into the corner with 1.5 min remaing on his clock and then stopped the clocks called the arbiter over and claimed a draw!! his opponent was livid He shouted i am two knights up? the Arbiter a strong 2200 elo himself tried to explain why but this guy was not having it ... In the end they had to get G.M Mark Hebden to come over and explain whey the position was drawn, let's just say the 2 knights guy was not amused and stormed out?? It's one of those Endgame positions worth study and knowing and there are decent youtube videos to help explain this ending!