Unable to add a directory and all its subdirectories to load-path in Emacs

Question

The question is similar to one.

However, it differs in putting all subdirectories achievable in the folder too.

Jouni's code which puts first level folders achievable

(let ((base "~/Projects/emacs"))
  (add-to-list 'load-path base)
  (dolist (f (directory-files base))
    (let ((name (concat base "/" f)))
      (when (and (file-directory-p name) 
                 (not (equal f ".."))
                 (not (equal f ".")))
        (add-to-list 'load-path name)))))

How can you put a directory and all its subdirectories to load-path in Emacs?

Answer 1

My answer in the other question does handle multiple levels of subdirectories.

The code for reference

(let* ((my-lisp-dir "~/.elisp/")
       (default-directory my-lisp-dir)
       (orig-load-path load-path))
  (setq load-path (cons my-lisp-dir nil))
  (normal-top-level-add-subdirs-to-load-path)
  (nconc load-path orig-load-path))