Apropos change: Two decades ago, US inter-city air travel could be done anonymously - now it can't. US inter-city rail could be done anonymously - now it can't. US inter-city bus still can (though given credit cards, it's much less common), but I've seen "everyone must show identification to state/federal police to get on the bus" drills at bus depots. On intra-city subway and light-rail, it's been the (very infrequently exercised, except during a Democratic party convention) policy that state and federal officers with dogs can do random ID checks and bag inspections, or if someone refuses, require them to leave the train. Years ago, that was unimaginable. Around Boston and Manhattan, office buildings often had no ground floor security at all, or it was concierge - you'd just wander in and up to some office, and talk first with some receptionist, or if they weren't there, maybe hit a desk bell, or maybe wander around the office asking for directions. Now you usually hit security just inside the building door, and often have to present state identification, which is sometimes scanned or typed in. And get buzzed into offices. Office workers badge themselves through turnstiles and doors. Locked doors are more of a thing than they used to be. Before laptops, what is someone going to steal? Office supplies? A heavy typewriter? Large CRTs? MIT used to emphasize it was an "open campus", and students felt guilty about not doing enough wandering around in the evening/night, visiting labs and talking with people. Now that seems no longer a thing - lab doors and even whole buildings are locked to them, even with cards, even during the day. If you walk by a bar in Boston on a busy night, you will see someone standing there, checking government-issued identification. A few decades back, pre-MADD, that wasn't a thing.

We become used to "the way things are" so very rapidly, that it's easy to forget that the same familiar place, a few decades offset in time, could have had startlingly different attitudes and practices. As much as living in a foreign culture today.