I'd had enough today and wrote nothing. I haven't given up, but I just couldn't bring my self to put pen to paper. I recognise this sort of blank day from previous NaNoWriMo's, so I just accepted that this was part of the process.
I decided I needed a different sort of stimulation, so I jumped on my bike and went for an explore in the East End. It was good to be moving, out in the warm evening air, and I saw plenty to get my creative juices flowing. After an hour on the bike I felt better and I know that I will return to the page tomorrow.
As a post-script, being clipped by a car wing mirror reminded me that there are more important things in the world to worry about.