i have that frustration too mate. mine loses shit and would forget his head if it was loose too, and he's 11. we'll have to see if he improves next year at upper school when he's getting transported - i pick him up myaelf now so I can prompt him. when I remember.
Inexplicably, they both showed up at the bus stop today with everything just right.
... coats on and fastened, gloves on (and on the correct hands too!), mufflers around the neck and tucked in, earmuffs on, hats on, bookbags on, etc ... everything just right!
Of course, I expected this phenomenonal display to be the result of a great deal of teacherly intervention, but I was wrong. My son said he had his coat on when he left school, but they did all the rest on the bus so I would not worry. I have rewarded them with a chance to take a terrorizing run through our craft supplies for the evening (lots of mess-making possibilities in there - one of their favorite rewards!).