What did he actually change in the sheet, just tracking receipts or did he add a column for what you already had at home? Curious if the savings came from the sheet itself or just from him paying attention more.

Saw a thing about how card fees quietly add up for folks who never carry cash.

Eh, that only works if the items are all the same kind of thing. Some stuff has to move together, like if one piece depends on another, so you can't just park it in a "later" pile and forget it. I split mine by what's actually active right now, not by a fixed number like 40. Otherwise the things waiting get stale and you lose track of why they were there.