心有靈犀一點通

Etymology
From one of 's “Untitled” (《無題》) poems:

The rhinoceros' horn is reputed to confer telepathic powers – it is thought to be extremely sensitive, able to pass stimulus information from its tip straight to the brain in an instant.

Idiom

 * 1)  two hearts linked as one; having minds that are in sync; two hearts beat as one; having great chemistry