[kbenson]

Well, it was close to 15 years ago now, so read "I'm doubly mad" as "when something makes me remember it, I feel sense of loss, both for what I could have learned if the situation was different, and how I've felt about it and myself over the years regarding it."

I'm mad about it, but in the weird way multiple years can change that into into something that's not quite the same as the word usually implies.