Long may you Grok...

To grok is to share the same reality or line of thinking with another physical or conceptual entity. First used by Robert Heinlein in Stranger in a Strange Land he explains: “Grok means to understand so thoroughly that the observer becomes a part of the observed. To merge, blend, intermarry, lose identity in group experience. It means almost everything that we mean by religion, philosophy, and science—and it means as little to us (because of our Earthly assumptions) as color means to a blind man.”

The Oxford English Dictionary defines grok as "to understand intuitively or by empathy; to establish rapport with" and "to empathize or communicate sympathetically (with); also, to experience enjoyment."

Heinlein coined the term as a Martian word that literally means "to drink", and had a much more profound figurative meaning that is hard for Earthlings to understand because of our assumption of a singular reality.

(much lifted from WikiP)