That I’m a lesbian (42yo, unmarried).
That I’m 6-10 years younger than I am.
That because I’m a “girl” they can run roughshod over me (dude, where I come from, they don’t give engineering degrees to wusses).
That I like, uhm, how to put this… well, let’s just say they’re very surprised to discover that my “need to concentrate” playlist includes stuff by Metallica and Rammstein and that’s the soft end of the spectrum.
That the way I dress for work is the way I like to dress. This is particularly befuddling when I’m in a job with any sort of dress code (I try to wear stuff with a minimum of style, but seriously, pumps? PUMPS? I only wear pumps because it’s a job requirement, I wear slacks because it’s a job requirement and I’ve been known to say and mean “if pencil skirts are going to be required, start looking for my replacement”).
That my mother and I have a wonderful relationship and are the best of friends.
That being a Catholic means I’m reserving myself for marriage.
That being from Navarra means I’m a Basque-independentist.
That being from Navarra means I speak Basque.
That my native language and my mother’s tongue are the same.
Catalan is a funny one: Catalans who have heard me speak Catalan but not Spanish assume I’m Catalan-as-first-language. If they’ve ever heard me speak Spanish, even if the first time was after months of mutual conversations in Catalan, then they relabel me as “Castillian” (meaning “Spanish-as-first-language”) and get surprised every time they hear me speak Catalan. Apparently you can be fully bilingual Spanish-Catalan only if your first language is Catalan, but my case is a bit more complicated: native language, Spanish; mother’s tongue, Catalan.
Those are the frequent, off-the-top-of-my-head ones.