h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I find it quite interesting to learn that Black Cats are lucky in Europe.
I am from the US, I once had a nice English girlfriend and she was quite superstitious, which I found quite silly.
I used to take every opportunity to tease her about her silly superstitions.
One day we were driving through penniment green and a black cat crossed our path... she let out a giddy little laugh and she was so pleased.
I found this quite strange because I was brought up with the "belief" that black cats were bad luck.
This led to a very heated discussion about the "luck properties" of the common black cat.
I started out trying to correct her flawed thinking, however, it became apparent that she actually believed the superstition.
From that realization I began to subtly tease her about it. It took her quite some time to realize I was teasing her because she was so wound up. She was not too pleased.
I still think about that day and inwardly smile. Ahhh the blissfulness of unswerving belief!

Oh I nearly forgot...
What is the deal with Magpies?
This same English girlfriend would salute them whenever she would see one. At first I thought it was cute. Then it just became quite idiotic. She was 27 years old and saluted magpies, religiously!

Someone please enlighten me on this "Magpie Saluting Phenomenon"

I found some references to a Magpie nursery rhyme in "Carpe Jugulum", one of the discworld novels, but it said nothing of saluting. It only referenced numbers of magpie.

Thanks.