A state of mind
A state of mind is when you're so confused you think you're in a different universe and your brain is trying to figure out which one it's in.
I was in a state of mind because I thought my teacher was talking to me and then I realized she was talking to the person next to me.
My friend was in a state of mind because he thought the clock was broken and then he realized it was just 12:00 AM.
My dog was in a state of mind because he thought he was chasing a squirrel and then he realized it was just a shadow.