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.