Food for thought

Why is it that no matter how hard you try to keep a baby's food on the highchair tray, it always ends up everywhere?! Then comes the usual argument:
'I'm not cleaning him, I did it last time'...

All down his front, under his legs, between fingers and toes, under chin, up nose, in hair... Then just when you think you got it all you find some hiding in an ear - or worse, half an hour later at nappy change you realise that food has an uncanny ability to find it's way through several layers of clothing and into a nappy, bypassing the usual route! :-p