A "theme" for the baby???

My sister in law asked me today what my baby's "theme" is going to be. At first I thought she meant for a shower or nursery so I just said "well we're thinking grey and coral for the nursery".
No. 
She means what theme will my child be? Like, if I said "ladybugs" that means I want her to wear exclusively ladybug shit. Have ladybugs all over her room. Nickname her Lady Bug. 
Apparently people do this?! This seems insane to me. 
I've been told repeatedly by my in-laws that it is common practice and I am actually the weird one. 
So I take to the Internet. What do you guys think?? Is giving your human child a theme for their life weird or totally normal?!

Vote below to see results!