I went the other way. I do not memorize anyone's number, just mine. Or, how it used to be before we had to know every incoming number (versus just outgoing numbers, which was pasted right next to the phone on the wall).

I almost never pick up the phone. If someone wants to reach me they will send me some (insert tech) message or leave me a voice message. If it is an emergency they should not be calling me in the first place - rarely in place to respond to the emergency.

I do keep family and friends' numbers in my contact lists and have a phone numbers in my wallet to contact when they find my body.