There are many substitions, which include "It'll get better if you don't pick at it," "Sometimes things just happen," and "There are a lot of things in the world that
you don't know about."
Terry Pratchett describes 71-Hour Ahmed as substitious, which "places him in a minority amongst humans."
— Taken from the page
everything2.com/title/substition, explaining substition according to Terry Pratchett, who
originated the term in the Discworld novel Jingo.