It will take at least 50+ years for the whole world to adapt. Like the guy above me said, some people don't even shop alone and some don't even make use of online banking at all. I think that as long as people are adapting to bitcoin every year, the value will keep on growing.
It will take decades for the people and governments in the world to get used to the digital currency system. It is not just about the coin, but the whole system.