No "rule" does not have an exception and the same applies here. It is a great sentiment and if one works on their issues and coping skills and mindfulness such a goal is attainable for many, if not even most. Some people have such trauma that reaching that level may never fully occur.
A good path to follow, but like all other good paths we should consider following, it is a challenging path to follow. Our past personal garbage inhibits our clear thoughts which we need to follow good paths. Letting go and accepting is what we should do, but that takes more determination than might appear at first.