The two strangest things... hm...
1st would be when someone I was roleplying with had a bunch of guys get onto an elevator... then the next day realized it was probably not a bright idea. Guy panicked and froze up and I pretty much had to roleplay his guys fighting their way out of an elevator ambush.
In addition to that, I had to do it in a way that was in-character for the chuckle-heads that stepped into the elevator in the first place thinking it was a good idea. Thankfully, that's like... an action-movie trope anyone who grew up in the 1990's should know.
The second one was when I adopted a character and they started developing some mechanical-AI sentience where their actions from like 3 years prior that I'd forgotten about were pre-emptively countering stuff people were doing... and they were continuing to act on that.
-Bonus points for taking down two skynet-expies with that character.
I was like, oh... wow... they really got me stuck in a corner... I better check these note-- mother of god... those poor fools are screwed and I didn't even know it yet. (even as I was making posts that were making things worse, while totally oblivious... I mean... how the heck was I supposed to know you could weaponize flirting like that?!)
-It's like accidentally putting a chessmaster grand-champion in checkmate. And all you did was smile, tell dirty jokes, and hand-out crackers with cheese-spread on them.
Seriously, all I had to do was login and the posts practically wrote themselves.
It's like pulling a Henderson, but you didn't make the bio, you're just the one hold-onto it for today and the creator didn't bother to warn you that the character was a self-aware Triple-Henderson meme that you now cannot be rid of (six years and counting TEN YEARS... fuck... she's able to manipulate time... RUN NOW AND SAVE YOURSELF).