Matt Gemmell, on productivity and concentration:
We are capable of productivity, though. I suffer from periodic insomnia, and even in the late afternoon of the second full day with hardly any sleep, I can produce valuable creative output. It’s by no means the ideal situation, but it’s possible. It’s also uncommon. Most of the time, unless I’m energised and fed and “in the zone”, focus is a struggle.
I remember a couple of years ago my cable box went on the blink and I had to wait a week for a replacement to be sent out. It turned out to be one of the most productive personal weeks for me in years.