From a probability lecturer whose brain moves too fast for his tongue, on the discussion of quantification of surprise:
"If I roll a dice and I get a heads, is this a surprising event?"
From the same lecturer:
"This is a table of the frequencies of words used in Charles Dickens' Origin of Species."
And my personal favourite, again from the same guy:
"Now we assume n is infinity. Hmmm... that might not be too realistic... [thinks] ok, so a realistic value for n might be about 40... But 40 is quite close to infinity."