Because "6, 7 ate".
Because every time he puts up a prayer it gets answered. (I thought of this myself, but it is so corny, it could easily be in every damn joke book.)
Because they're poor conductors! (I know they're called Engineers but cut me some slack, I thought of this in the 9th grade.)
It makes his Dagobah faster.
Because in charge of directing, Yoda was
It's 5 o'cluck somewhere.
I can't even...