There are exactly 6 phone numbers I can recall from memory, one of them is my grandfathers which I’ve known since I was little, the others are family members on my phone plan because we got assigned a block of contiguous numbers when we switched to T-Mobile.

The last (originally a) land line phone number I had memorized in childhood was quietly lost last year when my grandmother passed away. That personally seemed to mark the end of the era where I'd ever remember a phone number that wasn't one I punch into random "rewards programs" kiosks as an ID of sorts.