diff --git a/core/core-editor.el b/core/core-editor.el
index 909829556..724a32802 100644
--- a/core/core-editor.el
+++ b/core/core-editor.el
@@ -106,7 +106,10 @@ possible."
 
 (add-hook! 'after-save-hook
   (defun doom-guess-mode-h ()
-    "Guess major mode when saving a file in `fundamental-mode'."
+    "Guess major mode when saving a file in `fundamental-mode'.
+
+Likely, something has changed since the buffer was opened. e.g. A shebang line
+or file path may exist now."
     (when (eq major-mode 'fundamental-mode)
       (let ((buffer (or (buffer-base-buffer) (current-buffer))))
         (and (buffer-file-name buffer)
@@ -155,7 +158,7 @@ possible."
 ;; The POSIX standard defines a line is "a sequence of zero or more non-newline
 ;; characters followed by a terminating newline", so files should end in a
 ;; newline. Windows doesn't respect this (because it's Windows), but we should,
-;; since programmers' tools tend to be POSIX compliant.
+;; since programmers' tools tend to be POSIX compliant (and no big deal if not).
 (setq require-final-newline t)
 
 ;; Default to soft line-wrapping in text modes. It is more sensibile for text
diff --git a/core/core-ui.el b/core/core-ui.el
index b52adae8e..417349677 100644
--- a/core/core-ui.el
+++ b/core/core-ui.el
@@ -504,6 +504,8 @@ windows, switch to `doom-fallback-buffer'. Otherwise, delegate to original
                        all-the-icons-wicon all-the-icons-alltheicon)
            ""))))
 
+;; Hide the mode line in completion popups and MAN pages because they serve
+;; little purpose there, and is better hidden.
 ;;;###package hide-mode-line-mode
 (add-hook! '(completion-list-mode-hook Man-mode-hook)
            #'hide-mode-line-mode)
@@ -518,17 +520,19 @@ windows, switch to `doom-fallback-buffer'. Otherwise, delegate to original
 
 ;;;###package rainbow-delimiters
 ;; Helps us distinguish stacked delimiter pairs, especially in parentheses-drunk
-;; languages like Lisp.
+;; languages like Lisp. I reduce it from it's default of 9 to reduce the
+;; complexity of the font-lock keyword and hopefully buy us a few ms of
+;; performance.
 (setq rainbow-delimiters-max-face-count 3)
 
 
 ;;
 ;;; Line numbers
 
-;; Explicitly define a width to reduce computation
+;; Explicitly define a width to reduce the cost of on-the-fly computation
 (setq-default display-line-numbers-width 3)
 
-;; Show absolute line numbers for narrowed regions makes it easier to tell the
+;; Show absolute line numbers for narrowed regions to make it easier to tell the
 ;; buffer is narrowed, and where you are, exactly.
 (setq-default display-line-numbers-widen t)
 
diff --git a/core/core.el b/core/core.el
index 2359235ce..a954358ef 100644
--- a/core/core.el
+++ b/core/core.el
@@ -208,7 +208,8 @@ users).")
       inhibit-default-init t
       ;; Shave seconds off startup time by starting the scratch buffer in
       ;; `fundamental-mode', rather than, say, `org-mode' or `text-mode', which
-      ;; pull in a ton of packages.
+      ;; pull in a ton of packages. `doom/open-scratch-buffer' provides a better
+      ;; scratch buffer anyway.
       initial-major-mode 'fundamental-mode
       initial-scratch-message nil)
 
@@ -246,8 +247,7 @@ config.el instead."
 ;;; Optimizations
 
 ;; A second, case-insensitive pass over `auto-mode-alist' is time wasted, and
-;; indicates misconfiguration (or that the user needs to stop relying on case
-;; insensitivity).
+;; indicates misconfiguration (don't rely on case insensitivity for file names).
 (setq auto-mode-case-fold nil)
 
 ;; Disable bidirectional text rendering for a modest performance boost. I've set