One who has suffered dashed hopes about a career, relationships, or a combination of such challenges may feel that precious years were outright wasted and must be written off as worthless.
"Oh, well, no one's perfect" is a statement often made as an apology for human imperfections—occasioned, perhaps, by a forgotten appointment, a broken dish, or an idiosyncrasy.
If I were asked, as someone who was not raised a Christian Scientist, what betterments I especially thank Christian Science for, more confidence would be one of them.