I memorized my 16-digit library card, but on because it was the password required to access library dial-in unix computer system, which allowed some minor read/write access to the disk, but more importantly, unrestricted access to the internet via lynx, which was, for reasons unknown to me at that age, way faster than the AOL browser with image support.

Same thing with my first debit card. All the rest never stuck

Yep. I remember the big eyes of a bank clerk after she asked me to fill in some form regarding my card and I wrote the number without looking at the card.