To me i think there are some part of the world that still don't know anything about Bitcoin, because there are people in USA, UK, Australia, Canada, China,etc. even in Nigeria there are people that don't know anything about Bitcoin, they always think that Bitcoin is a scam, but people that know about it are making thousand of Dollars,($) I think they don't know that we are in a digital world now.
In Nigeria, yes I will believe you that there some parts of the country that didn’t know anything about bitcoin nor cryptocurrency which are mostly the rural areas where they don’t have access to network and probably no any civilization in the village.
USA, UK, Australia, China, and Canada you mentioned are hard to believe especially because of their advancement in any technology. They definitely know Bitcoin more than some of us but their governments are just too strict and are putting regulations on crypto transactions because of task and others. They should know Bitcoin wella because of its decentralized nature in order to avoid task and other charges from the banking sector.