Why do kids always leave it until the last minute to tell you they need something for school

Every time!

What is it with kids and waiting until the absolute last minute to tell you they need something for school the next day? It just feels like if my child has the option of telling me a week beforehand or a few hours beforehand they will always choose the latter and I know I'm not the only parent with this problem. Only last night my son decided to tell me he needed a costume for school the next morning. He has know since last week that he needed a costume for today but it just wouldn't be as much craic if I wasn't panic making a costume in the middle of the night. They don't wake up and choose violence, they stay sleepy and say nothing.   I think as parents we need to finally take a stand. I'm not sure how exactly. Maybe set up a fining system so they have to pay a fine every time they pull a 'oh I need this for school in the morning' stunt. Though this could cause more stress as who gives them their pocket money? Muggins of course. I'd suggest getting them a calendar so that they could plan ahead but seeing as they write it in their school journals and still don't say anything until the last minute just proves they are pure evil.   How many more last minute papier-mâché volcanoes, costumes and history projects will we have to make? How many more nights will we spend stress baking cupcakes for the bake sale we were only just informed was happening the next day? All I can say is the summer holidays can not come fast enough because if I have to hear 'mam I need this for the morning' one more time I think I might just scream.