> from someone older, who was in the 80s

There was the same amount of time, but it was allocated differently.

There were phone calls. If somebody calls you on the phone, you stop doing what you're doing and talk to them.

Apart from that, time was scheduled in larger chunks, with fever context switches. You watch a movie start to finish, not a bunch of 2 minute Youtube videos. You spend an evening printing photos in the dark room rather than two seconds on Instagram. You go to a chess club and play with somebody sitting across the table.

So generally you do one thing at a time for longer stretches, and have to plan those activities in advance.