I remember being a kid, yes I can remember that far back, and dreaming of the day in the future where we could carry around a small computer connected to a big network that had all of human knowledge so that it was always available, just like I would see in movies.
We are now living in the future, and so many people don't realize or appreciate how far we've come in 50 years.
As for remembering phone numbers, back in the day you only really had to remember a few, yours, a couple of friends, and maybe the pizza joint.
Then back in the 80s, home phones started having 5-10 saved number buttons, and it was always an indicator of how important your friendship was to someone - where your number was saved in that list / if it was.
I'm glad to have my contacts and calendar on my phone. As I get older, I find I'm relying on it much more often.
Pro-tip! If you like to bake, use your contacts app to store recipes! I have all my favorites as contacts so that I don't have to dig out a recipe book or card when I want to bake something