You Cannot Learn From What You Have Forgotten

NASA Has To Fight The Forgetting, NBC

"[Space workers] need the consequent inescapable ache of fear and the gnawing of doubt that keeps asking, over and over, if they've covered all angles and done all they can. And if their stomachs do not knot up, and mouths go dry, as they confront such decisions perhaps they need new jobs. They do not need comforting myths about "valuable sacrifices" and "space-is-very-very-hard" rationalizations for the failures of individuals and teams. And most of all, they do not need more human sacrifices to remind them of things they knew, but somehow allowed themselves to forget."