On November 2, 1815, George Boole was born, the English mathematician from whom we got Boolean operators. I teach Boolean operators by elaborating on this joke that I read somewhere in my first semester of library school:
If you send a librarian (or a database, as I tell students) to the store with a shopping list for sugar and flour and butter and chocolate chips, the librarian (or the database) will come back from the store with a cookie.
Sure, it's a nerdy joke, but it's a good jumping-off point and involves lots of pictures of delicious baked goods (flour AND chocolate = brownies, chocolate cake, chocolate chip cookies, chocolate croissants). I find this particularly effective when the class is right before dinner.
So, thank you, George Boole, and happy birthday! Read more about him here.