One serious drawback about letters is that, in order to get them, one must send some out. When it comes to the mail, I feel it is better to receive than to give.
Knowledge is a process of piling up facts; wisdom lies in their simplification.
You build on failure. You use it as a stepping stone. Close the door on the past. You don't try to forget the mistakes, but you don't dwell on it. You don't let it have any of your energy, or any of your time, or any of your space.