Meet your Waterloo
Arrive at a final decisive contest.
This phrase refers to the 1815 battle outside the Belgian town of Waterloo in which Napoleon Bonaparte was finally defeated by forces commanded by the Duke of Wellington. The term Waterloo quickly became synonymous with anything difficult to master. It was referred to as such the year after the Battle of Waterloo by another English hero - Lord Byron, in a letter to Thomas Moore:
"It [Armenian] is... a Waterloo of an Alphabet."
Yet another English icon, Arthur Conan Doyle, was the first to refer to someone meeting their Waterloo, in Return of Sherlock Holmes, 1905:
"We have not yet met our Waterloo, Watson, but this is our Marengo."
This refers to the Battle of Marengo in Italy, in which Napoleon 's forces were surprised by an Austrian attack and came close to defeat.