That's a new phenomenon though, people had to remember more phone numbers before mobile phones or built-in address books. From muscle memory alone, I can still

That's a new phenomenon though, people had to remember more phone numbers before mobile phones or built-in address books. From muscle memory alone, I can still finger dial about a dozen phone numbers belonging to friends when I was a kid, even though it's been 28 years since I last called them. Funny thing is that I can't recall the numbers without mock dialling them.