How is Charlie’s improved memory painful? If he had known how painful remembering would be, do you think he would have wanted the operation?

Charlie's memories bring up difficult things from the past, and his increasing intelligence allows him to understand things like he never has before. Suddenly, things that were once difficult have become painful.... understanding the hows and whys hurts. Listening to the tapes and looking back at past testing is also difficult, and Charlie's knowledge that everything he says, does, and writes are studied and analyzed now bothers him. Trust is an issue that comes into play for the first time.

The second part of your question calls for your opinion. There is no right or wrong answer.