Believe you can and you're halfway there.

 In 2006 my dad passed away and it woke me up. I was 218 pounds and needed to take my health serious, so I put on running shoes and started moving. In 2007 I ran my first race, the Flying Pig half marathon, and finished 11th in my age group without really knowing the sport. At that race I heard about the Boston Marathon and the qualifying standard and that became the target. After that I studied the science of running and learned how to train, fuel, recover and pace to get the most out of every mile. Training stayed consistent in snow, in rain, in summer heat. Qualified in the first marathon. Qualified in every marathon after that. Ran Boston in 2008, in 2013 and in 2014. This page tells the story of that journey. 

The link below is my verified career running results.  This link will take you to the external site:  Athlinks.com

Never ran the Boston Marathon?  This is what it feels like...