Part of the Common Lisp experience is tool building at the language level. You could be digging a hole with your hands. But thinking a moment, somebody came up

Part of the Common Lisp experience is tool building at the language level. You could be digging a hole with your hands. But thinking a moment, somebody came up with the idea of a shovel. That made a huge difference. Similar, tool building & usage at the language level can also make a huge difference. In larger applications this makes code much more compact and makes a person more productive.