When you feel overwhelmed or unfocused, what do you do?

Oh ya, I doubted more than expected. I had doubts all the time. The way was extremely, extremely difficult. … At one point I had to describe what I am doing to a person who is a great intellectual but not a scientist, and I told him what we felt is that we are climbing mountains in order to reach the climax – and these mountains are like the Everest, the biggest most difficult to climb – only to find out that there is another mountain waiting behind it to be climbed afterwards. So every climbing was an achievement but there was a bigger problem behind it or above it. I had lots of minutes that I didn't expect, but I thought science in general and this science particularly is worth the effort – even if we would never get the ultimate result.

Don’t sit down in the middle of the woods. If you’re lost in the plot or blocked, retrace your steps to where you went wrong. Then take the other road. And/or change the person. Change the tense. Change the opening page.