Grok: [ɡräk] to understand profoundly and intuitively.

"...the ability to grok more of the universe than that piece you happen to be standing on at the moment."

Robert Heinlein, Stranger in a Strange Land

The human cliché "This hurts me worse than it does you" has a distinctly Martian flavor. ... 'Grok' means to understand so thoroughly that the observer becomes a part of the observed—to merge, blend, intermarry, lose identity in group experience.

McGiveron, Rafeeq O. "From Free Love to the Free-Fire Zone: Heinlein's Mars, 1939-1987."