I swear he just started doing it on his own, I never indoctrinated him or even did much organising with him. But now if I want him to tidy his room, for instance, I just say, "Shall we go and organise your room?" and he's all over the idea like white on rice.
I tried to film him exulting about organising the other day but he was so hyper-excited you can't even hear what he's saying.
Here's what else he helped me do that day: I cut down empty 2-pint plastic milk bottles and used them (and a cut-down cardboard box) to organise our stationery baskets:
