Cruelty is seldom forgotten. You feel it as a child. Somebody takes away your toy or thoughtlessly kicks over your sand castle. A beautiful boy walks into your life, sees something he doesn't like or doesn't understand, and painstakingly endeavors to make you feel how much he hates you, to be constantly aware of the flaws that provoke that hatred. And then you grow older and wiser, but you don't forget the cruelty. You can't forget it, because there is nothing stronger, nothing more palpable in the human brain than the memory of mistreatment.
Cruelty is easy, and it breeds only misery. Kindness is harder, and you have to be brave to give it. To be cruel, you can stay closed off from everyone, wear a mask, but to be kind, in essence, to show love, you have to make yourself vulnerable, show your true self to someone and open yourself up to rejection.