You can say procrastination is the result of the core belief that one is not capable or will not perform the given task well, or once you do that thing, what will you have to worry about then?
I always wondered why the panic monster was so great at marshalling concentration, and so bad at defending against the wave of shame that comes once the task is complete and you wonder why you waited so long (again!!)
Panic monster is a tricky beast to use. In the early university years, looming deadlines could make me superproductive, though at an emotional cost. But after few years of using this, my mind became increasingly resistant, and now the deadline trick doesn't work anymore.
Regarding the panic monster, I noticed that the only music that can make me focus better than no music is ominous music. Specifically A.n.k.h. - I wouldn't listen to it for pleasure.
The latter rings true for me; I get a lot more done when I have a pile of stuff to do once I'm finished with the task at hand. If the task at hand is the only one left on my plate, I procrastinate, because what will I focus on after?