In earlier days the communication is very slow. There were no phones, no TVs, no internet and in some places even news papers were not available. Only text books and knowledge shared by the elders, parents and teachers are the only information available to younger generation those days. In case of any fought they have to approach teachers, elders or parents. The elders and others used to warn these people if they do any mischief and used to give the required information. Those days young people used to have either respect or fear for parents, teachers and elders.
These days there are TVs, phones, newspapers and above all Internet. So the younger generation is getting updated very fast. They need not ask anyone. In their smart phone they can browse Internet and get updates on any subject they want. Even I have seen some young people do the surfing about various ailments and curing medicines. They will cross verify the details in Internet. Their knowledge is very high and even more than their parents. That is the reason for telling that younger generation these days are fast.