The universe doesn't allow perfection.
It often happens that I have an idea, but then I try to fill in the intermediate steps and find they don't work, so I have to give it up.
The human race does not have a very good record of intelligent behavior.
One should love animals. They are so tasty.
There is nothing bigger or older than the universe.
I put a lot of effort into writing 'A Briefer History' at a time when I was critically ill with pneumonia because I think that it's important for scientists to explain their work, particularly in cosmology. This now answers many questions once asked of religion.