While a freshman in a Catholic private school, during religion class the nun SR Mary Truthfulness repeatedly said that the 'mass is the PERFECT unbloody sacrifice of the lord.  Over and over again she said the mass is 'perfect unbloody' sacrifice of the Lord'.  At the back of the class a hand was raised, which happened to be mine.  I asked;  sister did I hear correctly that the mass is perfect, the perfect unbloody sacrifice of the Lord...mind you, no one dared ask any questions in that class.  She peered over her granny glasses and said;  yes Walter I did.  To her I responded;  sister if the mass is as 'perfect as you say, I should only have to go once'.  Immediately, without hesitation she responded;  "my dear Walter, the mass is perfect, you are not".  From that point I had the most respect for her...I thought in my errant youth I had her nailed.