The girl you just called "Mudblood"? She spends hours practicing spells hoping people will like her. The boy you just stupefied? His parents use the Cruciatus Curse on him regularly. That kid you just pushed? He is trying to use the killing curse on himself. That guy you just made fun of for crying? His mother was killed by a Death Eater. Put this up for an hour, if you are against bullying in the Wizarding World. You never know what it's like until you fly a mile on their broom.