In October 2011 I was not able to complete a 5K walk that incorporated walking up 1000 steps (the annual Bisbee 1000, AZ). The next day I set out to lose 65 pounds and increase my strength and endurance so I can go back in 2012 and complete the walk. That is my motivation to "train."
For years I tried to convince myself that I needed to go to the gym to exercise. Fact is, I hate it and I would rather have a slap in the face.