That reminds me of a cool story, in Norvig's talk about Python...
When he finished Peter [Norvig] took questions and to my surprise called first on the rumpled old guy who had wandered in just before the talk began and eased himself into a chair just across the aisle from me and a few rows up.
This guy had wild white hair and a scraggly white beard and looked hopelessly lost as if he had gotten separated from the tour group and wandered in mostly to rest his feet and just a little to see what we were all up to. My first thought was that he would be terribly disappointed by our bizarre topic and my second thought was that he would be about the right age, Stanford is just down the road, I think he is still at Stanford -- could it be?
"Yes, John?" Peter said.
I won't pretend to remember Lisp inventor John McCarthy's exact words which is odd because there were only about ten but he simply asked if Python could gracefully manipulate Python code as data.
"No, John, it can't," said Peter and nothing more, graciously assenting to the professor's critique, and McCarthy said no more though Peter waited a moment to see if he would and in the silence a thousand words were said.
Though, may I add that Python (or any other modern programming language) can manipulate its own code as data - only not as gracefully as Lisp. In other words, a Lisp program is its own AST - but in other languages the AST is only a "parse" away (and Python specifically makes computing it very easy).
"... My first thought was that he would be terribly disappointed by our bizarre topic and my second thought was that he would be about the right age, Stanford is just down the road, I think he is still at Stanford -- could it be? ..."
I've often wondered why McCarthy has never been asked to Startup school to talk about developing and using Lisp and the advantages?