When nuclei are heated to extremely high temperature, they melt into quarks and gluons. The resulting QCD plasma exhibits some remarkable - and surprising -properties. I will summarize what we have learned about quark gluon plasma, and how its high opacity and perfect fluidity relate to strongly coupled or correlated systems in ultra-cold atoms and condensed matter. Mysteries abound in “how” and “why” quark gluon plasma works the way it does, and I will discuss how those questions can be addressed.