"Still, not all experiences create a positive change in a person. I'm not sure doing something to your brain which actually screws up the process of thinking necessarily leads to an improved thinking process afterwards, any more than breaking a leg makes you walk any better after it heals."

True. But would you (if you magically could, somehow) erase something really awful that happened to you from your memory. If John McCain could take a magic pill that would make him forget his years of torture as a POW do you think he would go for it? Even if that memory had the potential to cloud his judgement in the future (as some of his own party have suggested)? I don't think he would. I don't think I would either, although I can't honestly answer that for sure because I didn't go through that experience.

Everything that happens to us changes us, and not always for the better, but it is part of us and brought us to where we are now. The hardest-won lessons may be the most instructive of all.

Fortunately, the mind (if not the brain) heals faster than bone or muscle, and it usually heals stronger after being stressed. Some people even call it "building character". Besides, screwing up the process of thinking CAN be a good thing every now and then; just like we do when we get a good night's sleep.