David Heinemeier Hansson (?) held an absolutely astonishing key note at Startup School (set up by Paul Graham (?), founder of Y Combinator (?)).
It reminds me of a story about my dad, then a VC, getting advice from a well known swedish furniture magnate:
"Sören, you should be selling more rubber boots. People allways need rubber boots."
This was during the dot com boom, and we all know who turned out to be having some great advice.