My parents recently had an issue with their toilet, in which it was just getting clogged way too easily. It didn't take much paper at all for it to clog and need the plunger. They repeatedly used that liquid stuff that is supposed to dissolve clogs, but that was a temporary fix at best. My dad is no stranger to plumbing, and tried, I forget the exact procedures, but several different things, to no avail.
Finally, he and mom just took the toilet apart to physically look directly in the pipes, where they discovered...a spoon.
Not a big spoon, or even a soup spoon. Just a regular, ordinary spoon that would be put by a plate with a fork and a knife.
Apparently it had been causing a partial blockage and kind of moving around with the water, so it wasn't a consistent blockage and it didn't respond to clog dissolving stuff or any other traditional methods.
But how it got in there, or when, none of us have any idea. It's the same toilet that has been there since the house was built in the mid seventies (and yes, it is a lovely shade of avocado green!) and they have only taken it all the way apart twice before, both times a long time ago. I suspect it was that somebody was using warm salt water as a mouthwash for a while and somehow the spoon to stir it ended up in the toilet...but who knows?
And who knew a spoon could clog a toilet at all....or cause such a mystery?