Stephen Wolfram has the honor of having delivered the worst lecture I've ever personally attended (second worst: Stephen Hawking). I think he literally spent zero time thinking about what he might say. He spent an hour up there, typing things into Wolfram Alpha and sometimes being surprised they didn't work, then at some point showed, apropos of nothing, a crude chart of the times he'd gotten up each day. Looks he got that into Wired around the same time. This was one of the times when I realized that part of the secret of these wildly "successful" people is that are talented/lucky/hard-working enough initially to get credibility, then they shamelessly overcommit, picking a couple of things they feel like actually working on at any given time, and let everyone else down. I'm not even really disparaging the approach, since I, like everyone else, have to do it more and more as I get older. But, I was very disappointed at the time.