My Grandpa Is Zhao Jiadi

My grandpa's name is Zhao Jiadi. My great-great-grandfather went through the entire Kangxi Dictionary and spent a whole night coming up with the name Jiadi for him! But I'm not a Zhao. I'm a Li, and my name is Li Weiqi. I'm a legend of this era! Why is my last name Li when my grandpa's is Zhao? It all goes back to ten years ago…