Dreaming different dreams in the same bed

I've read this saying twice in the last two days, once in something written by a Korean, once
in something written by a Japanese. I'm curious to know if this saying originated in either
country, or perhaps China, or if it's actually a Western saying that these two Asians writers happened
to pick up.

Thanks in advance for any information.

Cea

I googled your phrase and came up with many references with 99% of the hits claiming it is Chinese in origin.
Below is a link to just one of them.

[Dead link - removed]