"Show me your flowchart and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won't usually need your flowchart; it'll be obvious." -- Fred Brooks
I recently started and finished a side project over a week and did so on a computer that I don't normally use. I was not logged into any of my normal 'social' websites and I found my productivity was very, very high.
It was quite an eye opener.
This may also have something to do with the fact that this was a novel and enjoyable project (for me) with a hard deadline, but there were a couple times where my brain was trained to go open up Reddit when I was stumped on something, and I immediately caught myself since it wasn't the normal page and got back to work.