There are a lot of folks commenting on my post, asking why it is important. I think you understand it. You want a wide palette of cultural idioms and metaphors in order to find better ways of connecting with your students. Otherwise it doesn't matter. People learn through taking patterns they already have and extending them. That means as a teacher you need an understanding of the common patterns your students carry around.

I envy you. Must be cool to get immediate, day-to-day feedback on your work, even if it wears on a person after a while.