We know UFC featherweight champion Conor McGregor loves to talk trash before and even during his fights. So when McGregor went in on Nate Diaz during the lead up to their fight at UFC 196 no one was surprised. McGregor’s attempt to clown Diaz for teaching kid’s jiu-jitsu classes fell flat for many especially former UFC welterweight champion and Brazilian jiu-jitsu black belt Matt Serra.