"20 Miles is Half Way"

In an interview before running the 2008 Boston Marathon, Lance Armstrong mentions that it was either Alberto or Johnny who told him that '20 miles is half way'.  

This is probably some of the best advice/insight into running a marathon that I've ever heard.  It becomes serious at mile 20.  It's painful at mile 20.  You need to seriously focus at mile 20.  You need to get ready by mile 20. Your blisters will show themselves at mile 20.  You will start to cramp up at mile 20.  The wall will be in view at mile 20.  

Yes, there's only 6.2 miles to go at mile 20 but at mile 20 you are half way there.