The seven-year-old has a very strong sense of order. It's been evident for years. As a two-year-old, he used to drink a bottle of milk while watching Bedtime Stories and Songs (a Sesame Street video). He knew that bottles were supposed to go in the sink when he was done. He had to get that bottle in the sink when he finished it. Some nights he be practically asleep, but he'd rouse himself to run into the kitchen and toss the bottle into the sink. Occasionally he'd drop the bottle and it would roll under the TV stand where he couldn't reach it. Then all hell would break loose and he'd throw a big fit until one of us retrieved it for him.
I've written previously about his tendency to confuse trash, shoes, and dirty clothes and put them all in the same place. I haven't mentioned the way he will jump out of bed in the middle of the night and pick up any dirty cloths off the floor. He knows that dirty cloths belong in the hamper. When we started toilet training him, he learned that when he took off a diaper it should go into the waste basket. Then we started putting underwear on him. The underwear also went into the waste basket. That was probably the origin of confusing waste baskets and laundry baskets.
The latest manifestation started a few weeks ago. He stared grabbing random items off the counters and tables around the house and throwing them away. We think he was saying that there was too much clutter. So we're trying to reduce the amount of clutter and increase the level of order. So far I've managed to get the kitchen counters cleaned off and keep them fairly clear for two weeks (a new record for us). I've also thrown out or moved to the garage a lot of stuff that was in the file cabinet and the storage cabinets in the family room. (Four years ago we took out all our bookcases when the seven-year-old went through a phase of pulling books off the shelves at random and tearing out pages. Now we have cabinets with doors instead).
I remember telling my wife a couple of years ago that we were probably going to have to become much more organized in order to thrive. Now the seven-year-old is pushing me to make that move.