I came late to the Harry Potter phenomenon out of obstinacy. I didn't want to read the books when everyone else was, precisely because they were popular. But I let myself get sucked in last year, and found that I really enjoyed the books!
I didn't watch any of the movies as they were coming out either. And now that the final movie is out, we've finally begun watching them. This will likely take a while, as our movie watching time is limited, and those movies are LONG!
But what surprised me the most, in watching it, is just how much they had to trim the novel to make it fit into the 2 1/2 hour time length. We watched Harry Potter and the Sorcerer's Stone last night. I was expecting a bit more Quidditch and a bit more of the time spent with the Dursleys on Privet Drive, among other things. (In the end, cutting both of those back wasn't entirely bad.)
Jeremy laughed at me while we were watching it, because at one point, I said "ooh, I gotta write that down!" See, I run one-shot Harry Potter games at some of the gaming conventions we go to, and there was actually a bit in the first movie that will fit perfectly into my next game. Of course, then my notebook was out, so I also wrote down something Ron said to Hermione: "You're a little scary sometimes, you know that? Brilliant, but scary."
Jeremy has decided that I really am Hermione. :)