I was watching a cat for someone who never came back to pick it up. We basically shared a space for a couple of years.
I had an accident and after a stay in the hospital with a broken leg, etc. I made it back home.
I immediately went to bed and after staring at me for a while the cat jumped up into the bed and tucked in right beside me - something the cat had *never* ever done before.
Once I was asleep the cat got up, walked to the bottom of the bed and sniffed my broken leg from my toes up to wherever. The cat sniffed for a long time and then came back - to the other side - and cuddled up.
I don't think the cat had ever cuddled up before in its life. The cat seemed to know that something was very wrong.
Cats seem to figure a lot of things out that we think they shouldn't be able to. I used to have a cat that was smart enough to hit the power button on my Mac II, wait for it to come up, bat the mouse down until it went into one of the screen saver hot corners, and would sit and watch the fish screen saver. Somewhere I have a videotape of this - I kept trying to figure out why I'd leave with the Mac turned off and come back to it turned on.
My current cat has figured out how to unlock my front door. (!)