Last Wednesday morning I took an hour to go and listen to a talk by Sigurdur Helgason at the University of Iceland. Sigurdur Helgason is one of Iceland's foremost scientists and a mathematician of great distinction, or so I am told. Suffice it to say that the American Mathematical Society have agreed to publish his collected works by some time next year---a honour that is bestowed only to true giants in mathematics.
I had the pleasure to meet Sigurdur Helgason in June 2004, when Anna and I visited Boston and MIT for Kári Ragnarsson's PhD graduation. He struck me as a very lively, curious and laid-back guy, who still enjoyed life, teaching his courses and thinking about maths despite being well over 70.
Sigurdur Helgason's talk kicked off a conference in honour of his 80th birthday. I had no chance of appreciating the technical content of the talk, but it was remarkable to see a 80-year-old man deliver such a well-planned presentation, reporting on some results he seemed to have achieved over the last four years or so. That was a truly awesome thing to witness.
What I found unbecoming was that there were no questions from the audience after the talk. Maybe the tradition in his area of maths is different from the one in TCS, but I would have expected at least the session chair to ask a token question to that great man.
Fortunately, being 80 and famous, he did not seem to be bothered!