A guy named Sloot claimed to have invented A system which could compress data down to 8/10^6 its original size with zero loss in quality.
People were skeptical, but Phillips agreed to buy the system. The day before the deal was to be signed, Sloot died of a heart attack, and the floppy disk on which key elements of the system were stored couldn’t be located.
Then there’s Starlite. The “Magic Plastic” lost due to its inventor’s unwillingness to part with the formula.
But those technologies are more lost than repressed.
Anyway, I am interested to hear if anyone has thoughts on how technologies like these might be recovered. And if you know of anything comparatively interesting, I’d be happy to hear about it.