KBP and his brother went down the street. KBP's brother stops and said: "Look KBP, a pile of sheet."
KBP: "It is not sheet, all lies."
Brother: "It is sheet."
KBP: "All lies."
Brother: "I give you 100 EUR if you eat a piece."
KBP ate, brother gave him money.
KBP: "You right, is sheet - now I give you 100 EUR if you eat piece."
Brother ate piece and got money.
After a while KBP's brother said: "Hm, we've just eaten sheet and earned nothing."
KBP answers: "You are right, however we had 200 EUR revenue, each!"