Do you have some sort of serious cognitive problem?
I guess I need to explain this like I were dealing with a mentally-challenged child.
Crazy nun hated left-handed people. My wife was and is left-handed. Crazy nun hit people who wrote left-handed. Because she was crazy and sadistic, she used a broken piece of a draftsman's square honed to a razor edge. The first time, it took my wife completely by surprise, which is why she did not react before the shank cut her. Immediately after wrapping her hand with anything she could to stop the bleeding, she decided there would not be a second time. Because the nun was used to dealing with terrified, cowed victims, she was totally unprepared for ANYONE to fight back and wound up in the hospital with a broken jaw.
If that's still too complicated for your limited intellect, tough. I cannot simplify it any more.