In the early Church, Christians were renowned for being like anyone else, not practicing any special customs, often not having a home city but living in and adapting to wherever they were, but their Church was open to all, and they wanted anyone and everyone to learn and believe in their new religion. Who wouldn't have talked about the Christians or their new religion and its ideas and principles, at that time? and some ask what the Church of today would be remembered for.
What today is worth talking about the way the Church was in those first couple hundred years? What do you tell people 'You just have to know about...' if you find out they haven't heard about it?
The only thing I can think of is investing, a trading account being so simple now, and investing so available and almost necessary as a way to manage savings.
Even travel, you don't 'just have to go see' anywhere now, since mass travel has bland-ized and homogenized locations.