Every now and then I see newbie questions like "How do I add : to the front of a symbol?" or "How can I add or remove parentheses from a list?" I couldn't figure out what frame of mind might produce that kind of question. Today I saw a StackOverflow answer that cleared it up for me. Approximately: Lisp behavior is defined for objects, not source code text. That concept is so thoroughly drummed into me that I don't think about it, but it's not a common concept among programming languages. If you look at Lisp code and think about its external representation as text, you might come up with those kinds of questions.