You can name any successful company, and you can point to a large group of people who said that the company was going to fail. Generally, humans have a bias to

You can name any successful company, and you can point to a large group of people who said that the company was going to fail. Generally, humans have a bias towards saying things are "impossible" or "sure to fail" with limited personal understanding of the nature of that thing. Indeed, people are more expert about impossible things than possible things...they have encyclopaedic knowledge of things that don't work (this is a safety behaviour that some are more disposed to than others). I have learned, through personal experience of getting this wrong, that people will surprise you more often than your pessimism will be justified.