I once left our cat at my son's and his wife's house, while we did some traveling. They were very kind to her, but I forgot they had this giant, evil, passive aggressive male cat. She literally was living in fear for a week.
When I walked in the bedroom she refused to come out of, she took one look at me, and jumped on me and started purring. She would not let me out of her presence. That night, she stayed right under me, as I tried to sleep. Then, I found out what I had done to her. That big male cat was head butting the door all night. I chased him away, but he just kept coming back. My cat got in her carrier the next day, and would not get out. She was going home or else! And home we went.
She missed me, for sure! But that cat was just another sign to her, that she was going to be my best friend forever.