Grok
Understanding something so deeply and intuitively that it becomes part of you — to comprehend through empathy and identification rather than mere analysis.
Origin
Robert A. Heinlein coined the word in his 1961 science fiction novel Stranger in a Strange Land, where it serves as a Martian term that literally means "to drink" but figuratively encompasses understanding, loving, and merging with something completely. The novel won the 1962 Hugo Award and became an icon of the 1960s counterculture. Grok quickly spread among fans, hippies, and later programmers, eventually entering the Oxford English Dictionary.
Everyday Use
Richard Feynman, the late physicist, had an expression, "If you can't explain it simply, you don't understand it well enough." To grok something is to have incorporated the concept so firmly in your mind that it becomes more than a tool, it becomes an extension of you. I try to learn something every day and to grok something until not only does it make sense to me, but to the point of owning it, whether a programming concept, a literary term, a historical event, or more.