Yeah...a while back we had a user upset by something or other who then commenced rampaging through deleting ALL his past posts, which naturally threw many threads into cryptic disarray. In response, the Admins at the time restricted editing or deletion of one's posts to one hour. There was an announcement of this change at the time.
Since then, I've joined the Mod Squad, largely to lend my size 11½ boot to the occasional "roach stomp" that is spammer control. But I think I can also edit others' posts, though I'd likely never presume to do so unbidden. Still, if that past post of yours is really keeping you up at night, shoot me a PM with a link to the specific post, along with whatever changes you'd like made to it or whether you'd prefer it deleted outright, and I'll see what my newly-acquired super powers can do for you. OK?