开一个（数学）玩笑

由于用英语表达更容易理解，所以就用英语写吧：

Q: Why everything tastes like chicken?

A: Because "everything tastes like chicken" tastes like chicken.

Proof:

"Everything tastes like chicken" is a set. S = {x | x tasteslikechicken}

This particular set ("everything tastes like chicken") contains itself because the set itself is an element of "everything".

Since "everything tastes like chicken" (as described), "everything", including this set, has to taste like chicken.

Hence, "everything tastes like chicken."

Q.E.D.