Been there. Done that.
Went to a family genealogy gathering.
Gentleman was giving a "lecture" on some of the proper mechanics of doing a search.
He stopped.
Stared into space for a short moment.
Caught himself, smiled, and said: "Sorry, I had a senior moment."
"Sometimes I have one..... that goes on for days and days."
Fortunately he finished his presentation with no further episodes! ;D