George Carlin quotes

I have recently started reading some great wit and wordplay by George Carlin, (an all-American comedy superstar, who I had never heard of before, except after I had heard of him). Apart from a lot of the usual observational humour, he has some great unanswered questions – here are three:
"Is there another word for synonym?"
"What if there were no hypothetical questions?"
"What was the best thing before sliced bread?"