“Finally managed to ressurect all my old documents from 1985-2000 which had been locked and unopenable (turns out they were DiskDoubled!). I used to write a lot of letters. Kinda cool and kinda creepy to see them.”
DiskDoubled was an old Mac compression utility from the early 90s — it would transparently compress files on disk to save space, back when hard drives were measured in megabytes and that mattered. If you didn’t have DiskDoubler installed, the files just looked like garbage. Mine had been sitting that way, unreadable, for years.