A few years back, I did have an issue when trying to pick a friend up at the airport and their phone died. I've had the same number for 25 years and they weren't able to call me since they didn't know my number...and they've known me 15 years! <sigh>Wives can be very handy in that situation ... except when I think about it, how would I phone her, even using someone else's phone I would be struggling because I've never memorised her number ... must revert to steam technology levels and write it down and keep it in my wallet!
I'm one of those people who memorized several phone numbers by heart so I know I'd be able to contact at least 4 or 5 people by memory. If I needed a different number, I suppose I'd call one of them and then have them make the call or give me the number I needed.