So this happened to me a few days ago. At my school's meal hall we have this thing where people pledge not to use trays for whatever amount of time for environmental reasons (logic is they save water with less trays to wash and if people don't have trays, they won't take as much food and thus waste less food).
So I decided what the hell I'd pledge for a day and see how it goes.
Well instead of taking less food I just tried to carry all kinds of plates and bowls all at once. In a shuffle of dinner plates I dropped a bowl of bran flakes and milk. OH NO! Wasted food! There goes my pledge for the day! Then just to make things hilariously worse, when I dropped the bowl it spilled allll over a stack of trays (which were there for the non-pledgers), which then in turn had to be washed.
So because I tried to be ecologically responsible, I ended up wasting a bowl of cereal and set the place back by about 20 pledges in trays that needed to be washed. Success!
Needless to say I now usually take trays at meal hall, you know, for the environment.