Technology and lifestyle I believe that technology is the basic cause. Technology changes people's thoughts, beliefs and consequently the lifestyle. Each and everyday you find new things around us so for sure you cannot live the same way as your parents did when they were young.
Change is something that human fears and that's why it's hard for parents to face it.
The other reason is that nowadays youth are more used to changes so they go for it themselves and they need adventure in their lives so they go for change themselves which parents can't stand.