Emacs prelude "smartens"
C-a by rebinding it to "crux-move-beginning-of-line"
My muscle memory likes the vanilla emacs setting better, where C-a moves point to the absolute beginning of the line.
How do turn off this specific prelude "smarts". ?
You can use that:
(global-set-key (kbd "C-a") 'move-beginning-of-line)
Since this is defined on prelude-mode, you can alternatively redefine this directly for this minor mode map:
(define-key prelude-mode-map (kbd "C-a") 'move-beginning-of-line)
If you don't want write any additional setup on your init file, as ultimate alternative you can just disable
M-x prelude-mode, but if you are using prelude I don't see this is as good thing, but you can anyway.