Awareness.

The term "zombie" aroused much derision in the past, before the apocalypse. Governments mocked and chastised their concerned citizens for asking for a small amount of revenue to be allocated towards a zombie safety plan. The odd professional (Max Brooks, or the intellectuals responsible for the mathmatical model mentioned before) recognised a serious threat, lobbied their respective authorities, and were laughed out of their offices. This is largely why when the outbreak occured, few were ready; almost all reacted innapropriately, and society as we knew it was extinguished. BUT DONT LOSE HOPE! Not all were caught unawares! This excellent public service announcement, done in 2010, shows that there were pocket demographics who were actively preparing for such an occurence. If you havent seen another human for days, understand that not all people were ignorant of the hazards of the undead! There WILL be survivors!
http://www.mnn.com/health/fitness-well-being/blogs/can-you-survive-baltimores-5k-zombie-run