Tights are not pants.
I saw a girl on the train the other day wearing a fleece jacket and a pair of tights. I couldn't help thinking, how is the girl walking around without any pants on.
If you purchase it in the lingerie department, it's not pants.
Edit: I just realized how funny this post would be for an English reader. So, in translation, tights are not trousers!
Edit #2: Awesome visual via gofugyourself.celebuzz.com:
Ok, now picture someone riding the train in this, only the dress/tunic thing is a North Face Fleece.