How does Eco find the time to write so much?

During the interview, Mukund Padmanabhan reiterates David Lodge’s astonishment on Umberto Eco’s large amount of works and how he manages to write them all. Eco replies that just like the universe has empty spaces, our lives too, have a lot of empty spaces or ‘interstices’, as he calls them. Whenever he has a few moments to spare in between two different tasks, instead of wasting them, he uses the time to write. He even gives an example of his working technique. He says that while waiting for someone to come up the elevator he keeps himself busy.