Yes Jannar, that is very common. I was a little taken back the first time my Dad said he needed to go home because Mom was frying chicken. I looked at Mom, my Mom, and it finally dawned on me that he was talking about HIS Mom. She died 27 year ago. Mom frequently will talk about how long it has been since she was home when in fact it was only a few days or talk about something that was going to happen when it already has.
Time and space and all those abstract thought processes go away rather quickly. This is the same part of the brain that rationalizes numbers. Mom was trying to count the number of blooms on the orchid plant I gave her and lost count at 7. She told me her puzzle had 500 pieces and "I don't know how many that is". I literally slapped my forehead on that one and just said back... Mom, that's a lot.
I hope you assured her that the refreshments were all taken care of and she didn't have to worry