...and it turns out that the HTML formatting for the spork had privately gone bonkers, leading to what should have looked like THIS:
<span style="color: rgb(0, 204, 255);">Jerry: Glargh. MORE sappy Aesops?</span>
instead looking like THIS:
<span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);"><span style="color: rgb(128, 0, 0);"><span style="color: rgb(0, 204, 255);">Jerry: Glargh. MORE sappy Aesops?</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>I wish I was joking.
So the ridiculous formatting chewed up an unholy amount of memory, and the "memory leak" fixed itself once I edited the formatting to no longer look like it had been vomited forth by a chatbot having a seizure.
Just a warning in case you experience a sudden browser slowdown while editing a rich text post that uses a lot of colors. Check the HTML tab - it may save you a lot of time and hassle.