So I'm safely in my room again, my keys in my pocket (I hope... yes). Here's what happened.
I think I must have laid down my keys somewhere while I placed my tub of (really really good) Einstein's smoked salmon cream cheese in my bag. I found the keys missing (strange way to put it) when I got to the Shedd, but couldn't do anything about it. So I tested stuff, and went luging, and luckily someone on the trip lives in the same dorm, and he let me in. At that time I was hoping my door was unlocked, and that I had simply left my keys in my room, which wasn't the case. I had to get my CA to open the door for me.
Because I don't have keys to the building, and because I had left over bagels and (really really good) cream cheese, I stayed in my room most of Sunday. I did a search of the lobby area, and found nothing. I asked my friend to search his car, and again had nothing. I was sort of resigned by that point that I had dropped them while pulling my bag of coins out to pay the meter at the Shedd.
Monday morning, since I knew I had a busy day ahead of me and won't get back to my room till past 2300, I told housekeeping that I had lost my keys. By university procedure, the lock to your room has to be changed, which was fine. I went out to class, came back at around 1700. The first thing I noticed is that they had already changed the lock; there was a notice on my door telling me my keys are at the house keeping office. Which was helpful, because they had already closed. So I sat in my friend's room for a while, and checked my email.
And found that someone had found and turned in my old set of keys.
So if only I had waited another day to report my lost keys, I wouldn't have had to pay anything for the lock. Perhaps if I had told housekeeping that I'm not sure the keys won't be found, I wouldn't have had to pay. But that is what happened.
Ah well. One can't have everything in life.