Well, when I was gone on vacation, my roommate told me that my cat would sit staring at the door forever each day, as if waiting for me to come back home. He'd be in the living room watching TV and cat would be at the door. Cat didn't do that when I was home. But cat did somehow manage to be at the door right away whenever I came home from work. Reason? Who knows, but I'd like to think the cat was waiting for me. :)
I try to not dwell on it because it makes me sad, but I had a cat I'm fairly certain knew he was sick and was basically waiting for me to get home from a vacation before he took a downturn and eventually passed. I've got four cats and the longer I have them around, the more I think there's more going on inside their little heads than the majority of people give them credit. They have good and bad days just like people.
https://www.theonion.com/vacationing-woman-thinks-cats-miss-...