I can't stop laughing

My son and his family are here from Birmingham for a few days and joined us with my daughter and her partner for the early church service on Sunday led by Rabbi Deborah Schloss (what can I say...we are Unitarians/Universalists) who led us in some wonderful Hebrew songs and liturgy.  I am sure this was all a new experience for my grandchildren but a good one.
After the service we all gathered in the Fellowship Hall for coffee and visiting.  A couple who are members were making a real effort to welcome my son and his family.  We don't know this couple well but appreciated their warm greetings.  My husband was eager to introduce our son to the man and said, "This is my brother.  We are twins but he is 5 minutes older than me which is just great.  It made my path much easier."  The man looked at Ken and my son who just turned 50 with a strange look on his face and said. "Must have been paternal."  My son is still cracking up over this.  I don't know if the man ever realized what was going on.  Maybe he is still pondering the birth of twins 30 years apart.
This happens frequently with Alzheimer's.  The patient can get the category (in this case, a relative) but can't find the right word.  But using the wrong word can bring up a whole other set of memories and they are off and running on another track and it is up to the listener to figure out where they went.  I like to call it a game of sorts.  Any suggestions for a game title?  Hearing is believing?