Ever dropped your child off at school or walked in the house after seeing your child off at the bus stop only to find a nicely packed lunch box still at home? I sure have!
My solution- as soon as I have my children's lunch boxes packed, they go right in front of the door they need to walk out of to get to school. I put the lunch box so in the way that they would trip over it to get out of the house.
(still looking for a way to keep my children from leaving the lunch box in the car when I drop them off at school though)