For me the lesson was that it's a mistake to try to slip obvious things past judges, and it's better to openly acknowledge where your case is weak. Also, once you're "caught," just talking faster doesn't help you.
Here's what Justice Scalia had to say about this in his new book Making Your Case: "Fessing up at the outset carries two advantages. First, it avoids the impression that you have tried to sweep these unfavorable factors under the rug. Second, it demonstrates that, reasonable person that you are, you have carefully considered these matters but don't regard them as significant."