There are some threads that should have died a natural death long ago, but just keep getting silly posts added.
There are also the occasional threads that I have no interest in even opening, and yet others do, keeping it at the top of a forum well past the best before date.
“Mute thread” is a lovely option. Thanks Discourse—people.
Thank the admins and staff at SD who decided to make the financial and technical commitment to move to Discourse! 
We’re just the tech janitors!
(But, it is true there is a special place in my heart for these forums since they were in the blog post I used to announce Discourse, and intentionally so – very high quality forums. Good people, trapped in grim Soviet-era brutalist concrete software!)