Big Bertha is usually confused with the Paris gun and was never actually fired at Paris.
In fact, Big Bertha saw very little action aside from bombarding a handfull of Forts in Belgium, most French soldiers who were captured from bombarded forts claimed
"No one can stand up to Big Bertha's might" when in fact they had never been shelled by Big Bertha at all.
You're an idiot, Big Bertha never even shelled Paris you dolt.
May also be a Bulgarian shot putter.
*Hannah calls Big Berta for help on a question*
Big Bertha then bends over to help Hannah with her problem. Upon noticing this, Jack calls to Boris and says "Boris, Hannah wants you," causing the unsuspecting Boris to look in the direction of Big Bertha's arse in its entirety. This is then rounded off with the majority of the class shouting "Whaaaaaay!" accompanied with many "wanker" hand gestures, leaving Boris feeling extremely stupid and traumatised by his experience.