"not even on other planets"

"But that was the kind of thing that happened when exploring unknown territory, when struggling through the mountains of terra incognita for the first time.  It was the kind of experience that humanity would never have again, not even on other planets.  Of course there were wilderness adventure tours these days being dropped in Alaska or Mongolia or the Himalayas without maps or compasses or GPS or radio, to try to reproduce that experience.  But no mater how they tried, Val did not believe what they were doing was really the same.  It was impossible to regain that mental state, of wanting to know and not knowing."

-- Kim Stanley Robinson, Antarctica