Do cats have bad days like us?

For a couple of days, our one cat, Max, just seemed miserable, wanted to be left alone and didn't want anyone petting him, talking to him or playing with him. Then when we got back either Saturday or Sunday, he was thrilled to see us and ran to his emery board and scratched out of excitement. He was talking to us, wanted to play and hung out with us.

Do cats have bad days like the rest of us?

Perhaps he wasn't feeling well or ate something that didn't agree with him. Can't recall when one of my cats had a bad day, but they can have days when they just are not feeling well and therefore, want to be left alone.

Glad to hear your cat is back to normal and thrilled to see you.

I'm not sure about "bad days". As Molly said, I've never seen my cat have a bad day unless she didn't feel well.
On the other side of things, I've seen one of my cats get majorly irritated that my sister left (moved out).
She only visits every once in a while and the oldest cat isn't too happy about it.

I believe they definitely have "bad days" as well as good days, moods, emotions, all of that! Cats are so sensitive! Have you ever seen your cat noticing things you would swear aren't there? They pick up on all sorts of energy and influences and it stands to reason they would respond.

And also of course it could easily be a physical cause such as eating something that disagrees, or even a small injury you don't notice, so it's a good idea, if you can, to check those possibilities too.