My life would be immensely less pleasant without any one of them. So they're staying.
I have no quarrel with the idea of tidiness. It has long been observed that in every couple there will be a tidy one and a clean one. Kondo is aware of this dichotomy, titling one chapter "Tidying is the art of confronting yourself, cleaning is the art of confronting nature".
Yeah, whatever. Here as in many other parts of this book, the words "mumbo" and "jumbo" leap to mind.
But it's true that in our house, I am the tidy one, and at least once a month my wife will find the clothes she left on the bed to wear that day have been tidied away while she was in the shower.
Or I've discovered the coagulating mass in a teacup I've put in the compost was a cube of pesto she was defrosting for dinner.
I had a kind of nervous breakdown and fainted. When I came to, I heard a mysterious voice, like some god of tidying.
She, on the other hand, apparently cleans all manner of household items while I'm not looking. I apparently don't notice.
So to be tidy and clutter-neutral is a good thing. But everything I needed to know about being tidy I learned from Ingrid Bergman, who gave her daughter, Isabella Rossellini, one simple, subtle and effective piece of domestic advice: Never leave a room empty handed.
There will always be something - a plate, a book, a pair of shoes - that belongs in a different room. Keep those items moving and your house will become and stay tidy in no time.
But Spark Joy is really a book about spirituality. Everything you read about it will emphasise its life-changing quality in religious terms. Accordingly, the pattern of Kondo's life follows that of most religious leaders.
The young Kando is different from the start - preferring to tidy books on the classroom shelves while the others are at PE, just as Jesus could be found arguing with the elders in the Temple.
Then, like Paul bound for Damascus, she has a breakdown from which she emerges transformed: "One day, I had a kind of nervous breakdown and fainted.
I was unconscious for two hours. When I came to, I heard a mysterious voice, like some god of tidying telling me to look at my things more closely."
Following this, she writes her Bible and sets out to spread the word.
Perhaps every generation gets the life-changing, sententious best seller it deserves, from Jonathan Livingston Seagull, to Your Erroneous Zones to The Secret.
As to changing my life, I prefer the advice of yet another now forgotten self-help guru, Superwoman Shirley Conran, who said life is too short to stuff a mushroom, to which I would add: or to fold underwear.