What do you do if...?

I noticed that a reader of Roslyn McMillan's new novel, We Ain't The Brontes, commented that she didn't get the title.

I personally thought the title was fabulous, since the novel is about sisters who write, shades of the famous Bronte sisters in the eighteenth century (there were actually three of them, but Emily and Charlotte were better known than their sister Anne). But I have read books where the author references something I'm not familiar with. I simply look it up. It's not a big deal, as long as it doesn't happen, like, on every other page, and when this does happen it's only been once in a book. It almost seems a shame for the significance of the title to go not understood and therefore unappreciated.

Have you ever read a book where you didn't understand a term or reference? Did you look it up, or just skip it and keep reading?