"What's the big idea?"  Einstein's theory of relativity (1905) states that energy and mass are equivalent.

"When will you ever learn?"  Babies are born with mute wisdom.  Their infant spirits are equipped with awareness and feelings, and they must simply develop in strength and skill.

"Do you believe everything you hear?"  Yes.  It's about as reliable as anything in print.

"This is the thanks I get?"  Yes.  I thought you wanted gratitude, not a gratuity.

"You don't expect me to go along with that crazy scheme, do you?"  Yes.

"How high is up?"  It's anywhere higher than you are.  It's also directly proportional to how heavy the load is.

"Is it just me?"  On a technicality, no.  One should say, "Is it just I?"  But then the answer would still be no, and you can prove it by looking in a phone book.

"Who died and made you God?"  Buddha did, for example, teaching that anyone could do anything he could do.

"What am I, chopped liver?"  Yes.  The human liver is divided by fissures into five lobes, so we are all (in part, at least) chopped livers since they are part of us.

"Are you looking for trouble?"  Yes, because the philosopher Hegel said that with the end of conflict will come the end of history.

"Do I look like I'm made of money?"  Yes.  If money can mean assets, then your organs alone look like tens of thousands of dollars.

"Is that a fact?"  That is not a fact, but is either a pronoun or an adjective.

"Is nothing sacred?"  Yes.  Atheism is a doctrine that there is no God.  However, many atheists are devout in their lack of belief, which makes them religious in spite of themselves.  So to them, nothing is indeed sacred.

"Who wrote the book of love?"  The Roman poet Ovid.

"Is the Pope Catholic?"  No, for two reasons.  The Pope is the head of the Roman Catholic Church, and is therefore not a part of it (if we define part as one of a number of equal quantities that compose a whole).  Also, the original meaning of catholic is universal.

"What is so rare as a day in June?"  The answer is "Every day in September, April, and November."  June and those other months have only 30 days each, so all are equally rare.  Rarer than a day in June is any day in February.  The most February can have is 29.

"What's eating you?"  Plaque is an accumulation of bacteria that forms on the teeth.