But what are the practical implications? What things can lisps do that nothing else can? Macros seem to be the biggest thing mentioned; pg says that was what let him write features so much faster than competitors. On the next hand he says he can&#x27;t imagine not having different types of items in a list.<p>And like Cypher, if you reach some higher enlightenment, then can&#x27;t use it (practical constraints) it just makes you want to go back. E.g. a friend that recently picked up F# now laments so much about having to work in C#; it&#x27;s now painful. Whereas a couple months ago, C# was pretty nice.<p>1: Though I&#x27;d like to see which features really made much of a difference.