Runners know that there is a tremendous difference in the mentality behind a sprint and a marathon. The sprinter uses up all his resources almost immediately, in order to go as quickly as possible. He knows he can recover afterwards. The marathon runner, however, maintains a slow and steady progression. He can't afford to chuck all his energy to the wind in the first mile.
I'm not built physically to be able to run marathons with ease, any more than I am naturally gifted with patience. I have unfortunately been able much of my life to procrastinate and then get through things with a sudden burst of brilliance.
Perhaps dogged persistance is less glamorous and fun, but it is part of adult existence. Life is an endurance race overall, not a sprint. This only makes sense for good stewardship, since the marathon runner achieves a much greater distance in the end.
The sprinter can see the finish line from the start. He keeps his eyes there and dashes for it like mad, ignoring everything that happens around him. The marathon runner sets small goals for part of the race, looks for people on the sidelines to cheer him on, and constantly drags his mind away from the pain in his body to the glory of the finish, even though he can't see it.
The sprinter doesn't take refreshment until the end. The marathon runner must constantly refuel along the way.
You have to keep going in a marathon, no matter how slowly. If you stop, it is ten times as hard to start again.