John as a Family Name

My father is Richard John and his oldest son is David John and his oldest son is William John.

John is a family name.  But when I asked my dad where his middle name came from, he didn't know. Our best guess is that it came from his maternal grandfather - Andrew John Klaich.  But as we have seen elsewhere, Andrew gave himself the middle name John.  For a while I thought this just came out of the blue (which doesn't make for a very great story).  

However, it looks like Andrew's younger brother was Jovo, was also known as John. Jovo was just 2 years younger than John and the sibling he grew up with.  He was also the only other sibling that came to America.  He died in America without ever having a family of his own.  I think that Andrew took the name John as a way to honor his brother who never had his own family.  That is a much better story than a made-up name.