Re: What about paper?
Having a paper notebook in a safe place is a good situation for using a written record.
But what's a safe place?
At one extreme is the sticky note on your office computer's monitor. That's the total insecurity that prompts "Don't write your password down" rules.
Stupid users, it seems, prompt stupid rules. I think, with my personal situation, I'd be more worried about the other end of the chain. The Twitter example resembles other cock-ups I know of, and it could be an instance of poor management of programmers. Specifications and documentation are critical weaknesses.