:(
Mental stability and resilience mismatch between bullied and bully. Bullies usually don’t see how their actions affect the others emotional wellbeing or can’t believe the magnitude of the effect. Education can fix this.
And then there are the sickest of the sick fucks who know about this mismatch and try hard to maximally exploit it to ends such as this. And they feel justified and blameless. It’s definitionally psychopathy.
Good rule of thumb: treat everyone as if their beloved mom just died. It’ll keep you from inadvertently being a dick.