who would have known
A rhetorical question used to express incredulity or surprise: who would have guessed it?; who would have thought that would happen?
Jaurès had over the last 8 days expiated many faults. He had helped the government in its diplomacy and, if war breaks out, he would have been amongst those who would have known how to do their duty...Quel crime abominable et sot! Raymond Poincaré
Who would have known of Hector, if Troy had been happy The road to valor is built by adversity. Ovid