I confess. If I know that a book is part of a series, I almost
can't read it until I read the first of the series and catch up. Moreover, if I like the series, I pretty much have to read it from start to finish.
I'm also like this with a TV series. Thank God they're releasing them now by seasons, and they're showing them endlessly on cable. I can go back and watch 24 from start to finish, or hop on at the series debut episode of The West Wing (as I did) and watch the entire show front to back.
Does anyone else join me in this aparently OCD habit? If there are enough of us, it's not abnormal!