Years ago when my millennial boys were toddlers, we went in for their scheduled immunizations. I had kept all their records in a folder for preschool, school, etc. This one day the nurse gave me a card for each of them where she'd put all their records together on one card with dates, etc. "Guard these cards with your life," she said, "These will one day be the same as their IDs." I thought it was weird since obviously they didn't have their photos on them like an ID would, and besides they were kids so they'd change appearance obviously. But she impressed upon me how important these cards were and I have them to this day. Of course, nobody at the DMV or passport office or anywhere else accepts them as a valid form of ID, but I've never forgotten that exchange. And with hindsight & what I know now, it's clear they were planning something like this 20 years ago.