Math was never my strongest subject. Physics, which I took in grade 11, was the bane of my existence. Chemistry I could more or less wrap my head around at the high school level. (More advanced, not necessarily, but I did fine in my grade 11 class.) But physics and my brain just never clicked. I passed, but barely, and I had to work my ass off to manage it.
As for list 2:
1) I haven't quite managed this one. Getting in my own way less is something I'm actually trying to work on right now. And as usual, I was wrong about Hannah, who seems better than me at letting herself be happy these days. I'm glad for her, and I'd like to make myself more like that. I can kind of remember the conversation I'd had with her that day, where we'd been out doing something, and she said to me at the end that she mostly didn't feel like she was enjoying her life, and didn't feel like she'd had fun that day. In retrospect, she was clearly trying to tell me that she was feeling depressed, but unfortunately I was too self-involved to see that at the time.
2) This directly contradicts all the assumptions I was making about Hannah in number 1. Nonetheless, I do think this is a good idea, and it is something I still try to live by.
3) I fantasized about telling Izzy off a lot, but I never actually had the opportunity to do it. I'm still not sure if that's a good thing or a bad thing--if it would have been cathartic, or just starting shit I didn't need to start.
4) This never happened. There were at least one or two times that might have been, for someone else, "real opportunities," but I never had the balls to try to strike up a conversation with Enigma Boy, whoever he was.
For list 3, while I still want (and an trying) to be a writer, I've moved away from the idea of writing for TV or having a comic book series of my own, for various reasons. A lot of these could apply to a novel series or whatever too, though, so I don't write them off. (Except the directly TV-related ones, and, for legal reasons, reading fanfic for an ongoing series in number 11.)
The Joss comment is referencing the significant change in Spike's claimed age over the course of Buffy, which at least once dropped by several decades. I love Buffy, but it did have some have some continuity issues (though I understand better now how that can happen when a show changes course, e.g. with Spike becoming a much more important character than he was originally intended to be).
Notice how I just assumed I would have my own series someday, and that it would be popular and I would be known as the creator--that I'd be a Name in TVland and/or Comicsland. And honestly, if I work hard enough, I still believe that could happen with one or more of the novel series I have in mind. Like I've mentioned, I've always been pretty ambitious.