I'd be shit out of luck using a payphone in today's world.

I don't remember anyone's phonenumbers except my teenage girlfriend's family, because while she has changed her phone number, the mother and brother were just 1 number off so I remember them, especially because the first 7 numbers are same as mine.

But aside from that, idk, maybe my own mother and brother.

But I haven't learned a phone number in fucking decades.

Pretty cool though as you know they're there, so either you can use the WiFi with your own device or just remember a few numbers in case you run out of charge.