For me it is not recording credentials with the assumption I would simply remember them later, while having every opportunity to archive them before eventually forgetting. Also, not keeping detailed enough notes & photos of exactly how my hardware is attached.
I once reset a computer and forgot I had a Bitcoin wallet on it. So I reset the drive and forgot to keep the home partition.
It had multiple Bitcoin back when it was less than 10ish. Mined with a bunch of people for the fun of it. Thought nothing of it until recently lol. That hard drive died a long time ago and is in some dump somewhere. I guess I helped keep the price for everyone else. So your welcome?
I see I’m not the only one with bitcoin woes and Linux lol.
Oh god!