Inside a home of the future you will be able to connect to a world wide web in which you can communicate with a global library system. Or, you can watch a cat playing a piano, watch other humans have sex while you beat your meat, or even perhaps argue with total strangers online regarding an esoteric concept you've only just heard about. The possibilities are endless.
How to blow the mind of 1967 civilian. Tell them that in 2020, 30% of the internet would be full HD, movie quality, videos of people banging each other senseless.
Imagine they knew that they could have personal updates from their president directly every 30 minutes, they would probably be quite happy no? If only the knew...