If every action has an equal and opposite reaction, doing evil should result in good. Shouldn't it? So if you want to be good to someone, you should do evil, as the opposite reaction would be good.
Though ironic, real life often works like that.
If you are 'good', like protecting someone from harm: They don't learn anything and the result/reaction is that they will harm themselves more a following time when you're not present.
Or if you are 'evil', insulting people for example: They could be confronted by things they're trying to hide from themselves. Forcing to face their own issues and deal with them.
The world really isn't that black and white, though. But this, at least, seemed funny to me.