I am at PPSN in Dortmund. I am listening to the talk on "Semidefinite Programming and Lift-and-Project Methods in Combinatorial Optimization" by Levent Tunçel. I do not understand anything at all of this talk. I am not the only one in the audience.
While I applaud the PPSN tradition of inviting people who are not evolutionary computation researchers to give keynotes, I don't think people outside our field understand how very little mathematics many (most?) people in this field know.
But the tutorials yesterday and the workshops on Saturday were really nice.