I will add the topic that my girlfriend would most assuredly add to this list: ...... Star Trek!
She has no interest in Star Trek at all, apart from making fun of it in MST3K-style.
YET it is incredible that every time she introduces me to one of her long-time friends, the subject of Star Trek and science fiction will inevitably come up and inevitably that old friend is discovered to have been a HUGE fan all along (and somehow that never came up during their longtime friendship). That old friend and then I go on to have a detailed Trek conversation while my girlfriend orders a strong drink and longs for a conversation about Gilmore Girls or NCIS....
I would also add endless tales about the children and grandchildren and what they are doing. While I do like to know what someone's kids are up to, I feel it is a bit sad when that is all a person has to talk about. I want to engage with the person I am talking with, not hear stories-without-end about what a child or teenager has been doing.
(Also, we just renovated our kitchen and two bathrooms last year, so we may be guilty parties in your book, Mirrorball Man
! Although we did much of the work ourselves, so much of the story would be humorous bits about how we messed up as we learned what NOT to do. No boring stories about picking out paint colors, trim, or floor coverings. Just stories about ceilings dropping in on us, bad wiring that should have resulted in our stove exploding, and things that we found when we tore out the walls.... )