Reminds me of Carl Sagan, and yet it’s by Gene Wolfe:
The brown book that I no longer carry with me, a book that has no doubt been destroyed with a thousand millions of others in what was the library of Master Ultan, had spun a tale of a great sanctuary, a place veiled by a diamond-sprinkled curtain lest men see the face of the Increate and die. After ages of Urth, a bold man forced his way into that temple, slew all its guardians, and tore down the curtain for the sake of the many diamonds sewn into it. The small chamber he found beyond the curtain was empty, or so the tale says; but when he walked out and into the night, he looked at the sky and was consumed by flames. How terrible it is that we know our stories only when we have lived them!