David Sirota of Salon writes a fence-sitting article on memory alteration that produces a single gem of a paragraph explaining why we are so wary to adjust our minds:

But, then, many also subscribe to the Nietzschian notion that “that which does not kill us makes us stronger” — an idea that has particular cultural traction thanks to the catechism of media deities like Oprah Winfrey. The bad stuff in our past, this self-improvement gospel goes, is what makes us not only who we are today, but gives us the “overcoming adversity” narrative to become better people in the future. Thus, by this dogma, taking a pill to simply wipe away even the worst stuff could inadvertently wipe away our best chance to make personal progress.