To inspire a singularity of focus, a challenge must be important to you and it must be something you feel you should do now in this moment. If it's trivial or not time-bound, you won't engage. So in selecting your next challenge in life, choose one that is meaningful and will demand your complete concentration.
Brendon Burchard (2012). “The Charge: Activating the 10 Human Drives That Make You Feel”, p.170, Simon and Schuster