This had somehow escaped my notice, but recently I was experimenting with a DRYing out my WordPress base theme and wanted to create some custom display logic for comments so I removed the call to comments_template() from my single post template.

I had assumed that all it really did was load the comments.php template from the theme or a fallback when needed. What I didn’t realise is that the comments for a given post or page are not loaded during the main query, but are queried directly in the comments_template() function. (The only exception is for RSS comment feeds which are loaded as part of the main query.)

The function is also responsible for stuffing the comments into the $wp_query global and setting the cpage query variables correctly.  It is a little frustrating as it means the theme must either some comment.php template even if it’s empty or recreate the comment display logic from comments_template().