I had a fake ride

Question: "if you take a baby to an isolated mountain, invite some actors to build an ancient village and teach him according to ancient etiquette... What will happen if you arrange him to come to a modern city unexpectedly when he grows up?" "of course it will be regarded as crossing." One replied "do ancient people know what crossing is?" The other man said "can you survive in modern times?" One person asked one day someone did such an experiment