Social psychology and especially 'a brief history of humankind', I lack the words to explain who amazing they are, seriously. Only been 2 lectures so far of history and he uses an evolutionairy theory + game theory approach as a way to matter of fact explain everything. It's going to sound controversial what he says to most people (it's what he says too in the intro) but it's completely and totally up my league of thinking and what I consider the only right way of approaching life. Learning so much.