I thought I wouldn't get much out of this book as I'm really quite good at cleaning, and take pride in discarding extra clutter often - but I honestly learned so much about why I hold onto certain things in addition to how to part with them. Also, it's weirdly easier to get rid of stuff when you hear that thousands of other people have exactly the same hoarding habits as you do. 
 There were some strategies described here that I know and do instinctively, but could never consciously articulate for people who ask me for help with cleaning and organizing, so I'm certain that they work because they work for me...and now I know why, concretely. Kondo has a couple of strange attitudes (makes storing clothes seem equivalent to a war crime, unsettlingly anthropomorphizes objects and homes), but she is never smug and comes across as sweet, especially since she constantly describes herself as lazy and slobby herself! 
 I listened to the audible version of this as I cleaned and it was very pleasantly meditative - the narrator has a soothing, even tone that matched the content of the book perfectly.