please don't leave litter lying around

I had the weirdest dream last night. I was driving somewhere with my dad... then I realized all the boxes of my stuff were empty... he got mad... yada yada yada dad called some crazy guy on the side of the road fat, and so then the guy started picking up sharp things covered in meat and running up, throwing them through my open window.
I think it's a valuable lesson to be more thoughtful to crazy people who are sensitive about their weight.
or a metaphor of Calculus...