What do you do when you can't remember a CURRENT guest? I called one of our female guests by the first name of the previous female guest.
I apologized and passed it off as a "senior moment".
She laughed and even made a joke about it in the guest book.
We have a little black board by the front door that says "Welcome" and we write each arriving guest's name. Everyone is impressed and thinks that we are just being thoughtful and welcoming. In actuality, I glance at the dang thing as I go out to greet them to remind me who the heck they are..