those who say it cannot be done should not interrupt those doing it

English

Etymology

Possibly come from a Chicago newspaper in 1903: “Things move along so rapidly nowadays that people saying: ‘It can’t be done,’ are always being interrupted by somebody doing it.” [1]

Proverb

those who say it cannot be done should not interrupt those doing it

1. people who dispute that a task is possible should not impede those people who attempt to do it