Cats die weirdly. In my experience, they get sick and pretend nothing is wrong for as long as they can. Then, they suddenly crawl into some hiding spot and try to quietly give up the ghost. Or when they're very plainly chronically sick (eg. renal failure, where they'll vomit all over the place, all the time), they might just drop dead on the spot, but not before trying to pretend everything is just 'super a-ok fine, I'm not nearly dead, what do you mean my hind legs are barely functional', for years.

Otoh we had a dog when I was a kid, and near the end you could just see the self-pity in its droopy eyes. 'No I will not go for a walk, can you see how miserable my existence has become? Woe is me.'

Possibly my favorite cat died two years ago after an extended viral illness. It was terrible. He was a feral cat and so lived outdoors in the summer heat. I had found him on the sidewalk, pulling his body with his front legs (his rear legs had failed). I carried his drooping form to his favorite spot in the front yard under the shade of bushes. I put ice in a towel around him to cool him.

Over the next two hours he lay there and cried to me as if to ask "Can't you do anything? What is happening to me?". I agree with you: they seem to know the end is near.

I could only pet him gently and talk to him softly, which seemed to calm him. His cat companion was quite upset, stayed around, but did not approach too closely.

After he died and rigor mortis set in, I retraced his path from where I found him back to our parking lot (a trail of bodily fluid remained). He had apparently been trying to eat something on the asphalt (I have seen this behavior before but don't know what it could be other than ingesting worms, bugs or plants, etc.) I carried his limp body to the front yard, dug him a suitable grave near a holly bush and lowered his body gently. His cat companion companion watched awhile but finally left, whereupon I lay the earth over one of the sweetest cats I've ever known.