PlatzhirschDe
PlatzhirschDe t1_j2dazip wrote
Reply to eli5 Circadian Rhythym. how do people that don't know what time it is when they fall asleep still wake up at the same time every day? by Master_Vannaka
Before civilization it was just important to be up in time - you needed to wake up in time to use what daylight hours you had. The specific time of the day wasn't as important - sure, you needed to know to some degree how late it was to plan your day, but before civilization there was simply almost no need to meet someone at a specific time when people were living in small tribes.
PlatzhirschDe t1_j2db709 wrote
Reply to comment by PlatzhirschDe in eli5 Circadian Rhythym. how do people that don't know what time it is when they fall asleep still wake up at the same time every day? by Master_Vannaka
And there definitely is some sense of time, although it might be very subjective. In my every day life I have trained to keep track of time in my head and I can usually estimate it within 15-30 minutes.