The only virtue worth instilling in a child is to acknowledge mistakes without shame and to correct them without perversity. If a vice is worth avoiding because it is dangerous, then in time it must manifest itself as a mistake; so all that is worth teaching is that if a mistake is shown to you, you should take it as a favor; and that there is no shame in a mistake, except loyalty to it.
To acknowledge a mistake is not the same as to reflect on it. Sometimes, when you have taken on a serious responsibility and made a mistake with irreparable harm, then indeed you should be asked, and should ask yourself, just what is wrong with you. But, for most mistakes, to reflect on the mistake is to compound it. Inevitably, if you do many things, you will make some mistakes: the only way to avoid all mistakes would be to do nothing—which is a mistake of life.
Capricious punishment is the most demoralizing condition possible: there is more cruelty in mild punishment for no reason, than in the harshest punishment for clear reason. Such punishment, if sustained, is too horrible even to rouse the will to die; it puzzles the will altogether.
To search out secret sins to blame for the statistically inevitable is to punish yourself with such random cruelty. And even when a mistake does follow on a medicable fault, self-reflection is the worst way to discover it. Reflection is so hard that, after the difficulty of the inquiry, only a dramatic answer seems plausible; so you end blaming depravity for what is due to indigestion.
The virtue must be instilled, because it is difficult to acquire. It slows the development of a sense of identity; for the contempt for the corrections you receive from certain kinds of people is how you distinguish yourself from them. It is probably impossible for an unpracticed adult to acquire, since to do so would be to have to bear to think that what seemed the limits made by nature were only the perimeter set by prideful error.
This virtue is so rare, and so unreliable even in those who sometimes have it, that you may ask if it is worth having at all. I cannot assert that it is. Can it really be good—if it is right, is it wise—to be without shame among those who blame you? And though this virtue removes self-set limits, it may thereby only cost you more time making slow progress where your talents do not lie, than if you have, at the difficult outset, simply chosen pride in your incompetence.
Yet I believe it is a virtue; the more so because, like all virtues, it can be immoderate. A little uncertainty about your nature saves you from overspecialization and obsolescence; and a little time wasted in spreading your roots, saves you from exhausting the soil.