Accidents cause History.
If Sigismund Unbuckle had taken a walk in 1426 and met Wat Tyler, the
Peasant's Revolt would never have happened and the motor car would not
have been invented until 2026, which would have meant that all the oil
could have been used for lamps, thus saving the electric light bulb and
the whale, and nobody would have caught Moby Dick or Billy Budd.
-- Mike Harding, "The Armchair Anarchist's Almanac"