[A] surfeit or some other cause had chanced to afflict him with a hiccough, which prevented him from speaking; and he could only just say [185d] to Eryximachus the doctor, whose place was next below him, “I look to you Eryximachus, either to stop my hiccough, or to speak in my stead until I can stop it...[snip] Start away with your speech,” said Aristophanes, “and I will do as you advise.”--Plato, Symposium.
In 2003 I got my lucky break; my alma mater invited me for a job talk. The week-end before the talk, I went to Miami Beach to visit my family. I claimed that time on the beach was the best form of preparation for my lecture. Then in a fit of entitlement, I invited the woman, which I had been dating for (at most) two weeks, with me to Boston--we drove up in my convertible, and partied around town while staying in a fancy hotel courtesy of my generous hosts.
I blew the job-talk.
I do not recommend looking in the eyes of people that you know want you to succeed and that you have just let down while you are making small talk with their junior, disinterested colleagues. For the next two years I felt like an ass, praying I would get a second chance in the profession. Since, I treat every talk as an opportunity to give the talk I should have given in the Spring of 2003 in Medford (corrected for experience, new insights, better self-awareness about what works, etc.). By this I mean that I should be in the position to succeed. (As a proxy, I use the idea that somebody in the audience has to be eager to invite me back.)