Darren Strange tells a delightfully honest story about a presentation gone horribly wrong, and getting back on the horse again. It illustrates something most veteran presenters can tell you: it takes more than one huge mistake to completely wreck a presentation. But the trick is that each mistake you make increases the chances of making more, because you get tense and worried and panicked as things go wrong. The comments to Darren's post are very helpful, pointing out that the failed demo was in some ways a smaller problem than the tone setting at the very start of the presentation. Something for all of us to learn from this one.