This one deserves to be engraved somewhere prominent:
"If something is fun, as someone else said, it is either immoral, expensive or fattening"
(P.G. Wodehouse in "The girl in blue")
This one cannot ever be erazed from my memory.
"How does a black buffalo eat green grass, have red blood and yet give white milk? That pa is the wonder of god"
(An old high school teacher of mine, and a constant source of rib-cracking amusement amongst us students).