Memorize phone numbers

How many phone numbers do you know by memory today? Only yours? Maybe a few family or close friends’ numbers? 

Memorizing phone numbers used to be fundamental for daily communication since phones didn’t allow saving numbers, or their internal space couldn’t register many archives. 

Although this habit may have gone underutilized since today’s smartphones can store so many things, including hundreds of contacts, it can still be very useful to memorize a few phone numbers in case of an emergency.