What is this called? Serious question....

What's it called when you and a friend, acquaintance, cousin, etc have 50-11 non-hobby things in common? Like your dogs have similar names, have siblings with the same name, almost identical nicknames (they sound the same)... There's more but it's a lot! And she didn't know HALF of this stuff about me! LoL!

Yes, this is about me and one of my close friends.