On the positive side, one can also study the works of brilliant minds... like the original work on the Common Lisp Object System and its metaobject protocol. It added support for object-oriented programming to Lisp and was originally developed with a prototype implementation, which could be loaded into a running Common Lisp.

https://mitpress.mit.edu/9780262610742/the-art-of-the-metaob...

The toy implementation from the book: https://github.com/binghe/closette

A real implementation, here for SBCL: https://github.com/sbcl/sbcl/tree/master/src/pcl

> CL is like clay,not even lego bricks.

There is also the "Big ball of mud" metaphor, which is attributed to Joel Moses, comparing it to the diamond like structure of APL:

  "Lisp, on the other hand, is a ball of mud.  It looks ugly, but you
   can add stuff to it without changing its character."