"Pain is inevitable, suffering is optional". I'm sorry, though I suppose it's tempting to hope that something good can come out of physical or emotional pain, I find this a very difficult concept. In reality, can little children being blown up, losing limbs or losing their parents, really be thought to be able to benefit spiritually, psychologically, intellectually or emotionally from such trauma?
I, and I expect many people, have on occasion found themselves fleetingly hoping that someone who has hurt them gets their "comeuppance". Though it may be a common and sometimes understandable reaction, I don't really think it's a very admirable or healthy one. I think to experience pleasure at hearing the news that someone is slowly dying from a horrible illness is quite chilling and I believe that feeling such bitterness must be quite corrosive.