Quoting Devil Duckie:" William is boring, but it's not horrible. I cannot, absolutely cannoooooot stand the name Caine. ... [snip!] ... it's first name. My children have funny NN's because their names do not shorten, But I'd never call them Sage and Douglas. "
I call my older two kids by their middle names. SO and his brother both go by their middle names. My oldest goes by her middle name because she shares a first name with two of my aunts, and it would have gotten confusing. My son uses his middle name because he was named for the son of one of SO's really good friends, and we didn't want THEM getting confused. My youngest goes by her first name, though.