In a less thought-provoking post, my toilet over-flowed again this morning. Fortunately, I caught it making overflowing actions (I am attuned to my toilet's peculiarities), and flushed clean water to test, and the clean water over-flowed. I'm getting a plumber in this time. I am so sick of having to watch the toilet every time I flush to make sure it doesn't do that. I'm calling my landlord in ten minutes.

Update:
I knew it! The plumber said it wasn't clogged, it's "limed up." From the hardness of Iowa City water. He said he could either replace the toilet (or whatever part is "limed up" - I was too busy being vindicated to pay close attention), or do some acid wash thing. I'm pretty sure I know what my landlord will do - my toilet's going Eighties, baby!