Composer John Adams writes an interesting blog (Earbox.com) about many things relating to composing.  In his latest post, he talks of the power to concentrate when composing:

The power to concentrate is a gift. I believe that being able to sustain it is largely the result of self-confidence. If you doubt the power of your intellect or doubt the quality or value of what you are doing you are much less willing to “stay with it.” You’ll find that what you’re doing is a chore, a painful, grinding obligation. In these circumstances concentrating is a task, an unpleasant struggle that actually, physically hurts. There’s always a part of you that is begging for relief, ready to jump ship at the slightest prompt, cut yourself loose from the humiliating confrontation of your pitifully weak brain with the intractable material you’re trying to manipulate and create meaning out of.

Alternatively, when you’re “on,” when you’ve found the groove, concentration ceases to be a matter of pain, ceases to be something you wish to avoid at all costs. Instead you’ll experience its opposite, a state of pleasure in the brain, like a sustained presence of endorphins.

Sounds very familiar!  I’m glad to hear such a talented composer describe some of the same problems.  His last paragraph is great advice for all of us:

Either way there’s no avoiding the task ahead for me. There will be a thousand potential distractions, digital or otherwise. Time to take a deep breath, withdraw from the social network (the grandest, most elaborate concentration-buster of all) and force those neurons into order.

Gotta get back to work!