I read a lot. Not as much as I used to, nor as much as I'd like, and certainly not as much as some other people, but I'm pretty sure I read more than average. Some books I just read once and then move on. Some move into my head and set up housekeeping; they become a part of me and I revisit them often, sometimes cover to cover, sometimes just random sections while I'm waiting for the pasta water to boil. Some I go back to because I love the characters (Patricia Brigg's Mercy Thompson series, Diana Gabaldon's Outlander series, Tad Williams' Memory, Sorrow & Thorn, Gaiman and Pratchett's Good Omens). Sometimes it's the writing (Patricia McKillip, Barbara Kingsolver). Sometimes it's the world created (Robin McKinley, Jennifer Roberson).
So, what is it that keeps Stephenie Meyer's Twilight series in my head? I've read all four books, twice, and bits of it keep popping into my head at random, inconvenient times. I don't think it's the characters, unless sheer mysteriousness is enough to do it. Bella's a bit of a whiner and distressingly immature at times - something she might be forgiven for as she's a teenager. Edward is annoyingly uncommunicative. Their relationship, which appears to be founded on not much more than "She smells nice" and "He's beautiful", goes from "I must ignore you exist to preserve my sanity" to "I'd rather die than be apart from you" in record time for no reason I really see. I get attraction and hormones and all, but it seems a relationship that's going to last for all eternity needs a little bit more of a foundation.
It's not the writing. I'm not a great judge of writing, but this case is rather unremarkable. I don't know I'd go so far as Stephen King has, although his is usually an opinion I trust on such things. (His theory for the series' popularity is that it makes sex less frightening for pre-teen girls. I don't have enough psychology to argue with him, but I don't see it. Edward is stubbornly Victorian when it comes to sex. When they finally move beyond kissing and cuddling, it's post-marriage and it promptly results in a pregnancy that is both Bella's death and transformation. As a result, the sex in these books - mostly left to the reader's imagination - is terrifying. Maybe it's the kissing and the cuddling which are being made palatable to readers who have just recently moved beyond cooties and if-you-like-a-person-hit-them-in-the-shoulder...)
I'm not even sure it's the world created. It's a lot like Reality, except for the whole vampire thing. Meyer has put some new-to-me-spin on the vampire mythos, which was fun. But it's really a very basic story: Girl feels Unspecial, mysteriously attracts attention of Most Amazing Boy, and ultimately discovers she's the Most Special Of Them All, or at least Starts to See Herself Clearly. I think this territory was thoroughly covered in the 1980s with movies starring Molly Ringwald. I presume it's being covered again each decade, and maybe Twilight is the vehicle of this decade. I guess I'm not keeping up with the kids these days.
Maybe it's because there's some part of me that hasn't really gotten over how storybook my teen years weren't. I hope I was never as whiny or trapped in inaction as Bella tends to be, but I understand her outsider status, her belief that she's nothing special. Has anyone ever stood outside the In Crowd and not daydreamed about being pulled into that magical world by someone who sees something no one else does? There probably isn't enough money in the world to convince me to be a teenager again, but there seems to be some irrational part of me that hasn't let go of that daydream. So, I guess that's the itch Twilight scratches.
Kinda sad, really, to realize that some things I'm just not getting over. Maybe by the time I'm forty... Goals are good, right?