Explain the difference?

Going to sleep at 6pm and waking up for a couple hours during the night before going back to sleep

Vs

Going to sleep at 6pm and waking up for a couple hours during the night before going back to sleep.

I'm pretty sure it's the same thing.

And it was never common for people in their 20s.

Younger children and old people body clocks naturally do it.

It's not some lost art, it's an afternoon nap