What I have learned from life is to make the most of what you have got.

Time travel may be possible, but it is not practical.

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.

I don't want to write an autobiography because I would become public property with no privacy left.

Don't be disabled in spirit as well as physically.

The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load.

Save water. Shower with your girlfriend.