(defun my-toggle-arrow-key-functions (&optional arg)
  "Enable or disable the arrow keys.
Called with no arguments disables the arrow keys.
Called with a non nil argument enables the arrow keys.

Used to force yourself to keep your hands on the home row for
basic navigation."
  (interactive "P")
  (cond ((null arg)
         (global-unset-key (kbd "<left>"))
         (global-unset-key (kbd "<right>"))
         (global-unset-key (kbd "<up>"))
         (global-unset-key (kbd "<down>"))

         (global-unset-key (kbd "C-<left>"))
         (global-unset-key (kbd "C-<right>"))
         (global-unset-key (kbd "C-<up>"))
         (global-unset-key (kbd "C-<down>"))

         (global-unset-key (kbd "M-<left>"))
         (global-unset-key (kbd "M-<right>"))
         (message "Arrow keys disabled"))
        (t
         (global-set-key (kbd "<left>")    'backward-char)
         (global-set-key (kbd "<right>")   'forward-char)
         (global-set-key (kbd "<up>")      'previous-line)
         (global-set-key (kbd "<down>")    'next-line)

         (global-set-key (kbd "C-<left>")  'backward-word)
         (global-set-key (kbd "C-<right>") 'forward-word)
         (global-set-key (kbd "C-<up>")    'backward-paragraph)
         (global-set-key (kbd "C-<down>")  'forward-paragraph)

         (global-set-key (kbd "M-<left>")  'backward-word)
         (global-set-key (kbd "M-<right>") 'forward-word)
         (message "Arrow keys enabled" ))))

Then I place (my-toggle-arrow-key-functions) in my .emacs file.

When I want the arrow keys back I just type “C-1 M-x my-toggle-arrow-key-functions ” and the arrow keys are back untill i type “M-x my-toggle-arrow-key-functions “.

How?
like this “\”?

(defun my-toggle-arrow-key-functions (&optional arg)
“Enable or disable the arrow keys.
Called with no arguments disables the arrow keys.
Called with a non nil argument enables the arrow keys.

Used to force yourself to keep your hands on the home row for
basic navigation.”
(interactive “P”)
(cond ((null arg)
(global-unset-key (kbd “”))
(global-unset-key (kbd “”))
(global-unset-key (kbd “”))
(global-unset-key (kbd “”))

(global-unset-key (kbd “C-”))
(global-unset-key (kbd “C-”))
(global-unset-key (kbd “C-”))
(global-unset-key (kbd “C-”))

(global-unset-key (kbd “M-”))
(global-unset-key (kbd “M-”))
(message “Arrow keys disabled”))
(t
(global-set-key (kbd “”) ‘backward-char)
(global-set-key (kbd “”) ‘forward-char)
(global-set-key (kbd “”) ‘previous-line)
(global-set-key (kbd “”) ‘next-line)

(global-set-key (kbd “C-”) ‘backward-word)
(global-set-key (kbd “C-”) ‘forward-word)
(global-set-key (kbd “C-”) ‘backward-paragraph)
(global-set-key (kbd “C-”) ‘forward-paragraph)

(global-set-key (kbd “M-”) ‘backward-word)
(global-set-key (kbd “M-”) ‘forward-word)
(message “Arrow keys enabled” ))))

Then I place (my-toggle-arrow-key-functions) in my .emacs file.

When I want the arrow keys back I just type “C-1 M-x my-toggle-arrow-key-functions ” and the arrow keys are back untill i type “M-x my-toggle-arrow-key-functions “.

I don’t understand eval-and-replace. I understood what it does, but I can’t ever imagine needing to use it. I often use C-u C-x C-e, but would never imagine deleting code I wrote. What’s the situation?