Everyone's talking about the internet, but cellphones are just as major a change. When you left home you were on your own, with no way to contact anyone other than finding a payphone somewhere. Have a breakdown or flat and pull off to the side of the road? Gotta wait around and hope someone helpful comes by, or else start walking. Meeting someone and they don't show? Go all the way back home and call them.
It had benefits too — you weren't expected to be on call or reachable 24/7. There was definitely a freedom in that, which has now disappeared. If you wanted to get in touch with someone and they weren't home, too bad…you just have to wait until they get home.
And that's just the actual phone part of the changes brought about by cellphones.