Up until relatively recently, time zones didn't exist, people set their watches by the sun at high noon and / or by the train pulling into town, once we had trains. It is crazy to think how little time mattered 200 years ago and how much it matters today. It also gives a certain perspective to different ways of thinking (ie Eastern vs Western concepts of time that have changed as technologies and industries have been adopted).
"Up until relatively recently, humans didn't really have a practical use for time periods as short as seconds. "
Well, maybe not measuring seconds with a stopwatch, or timing the start of TV or radio shows, but seconds were certainly of practical importance to our remote ancestors if they were being chased by a sabre-toothed tiger, say.
Most people still don't.