Just who was Ignaz Semmelweis?

Seth Godin has a great post about Ignaz Semmelweis.

Who was he?  He was the dude who figure out that you will save lives by washing your hands before assisting mothers giving birth.

Seth goes onto give examples of Galileo, txt’ing while driving and appreciating expensive wine as ways in which human nature is happy to be ignorant to the most basic human facts.

What basic fact have you ignored today?