Mid 30s and I feel ancient right now.

Generally, yeah. Your initials and family name - of the account payer only. First line of your address. I think the Terminator film, amongst others, shows this being used to locate someone.

You could opt out of being listed, but anyone who did that was considered a weirdo hermit. Why would you not want someone to be able to call you?

Oh God, it feels so weird saying it nowadays.

Yup. Totally real. It's all essentially public information to begin with. You have to have an address for taxes, and deeds need names on them. So there's a certain degree of information that's going to be available to pretty much everyone, if they go looking.

Phone books were useful at one point, though less so for individuals. They're still useful for local businesses.

Yep, which allowed us to make great prank calls because people wouldn't expect us to be calling them since they hadn't given us their phone number. If someone had a popular name, like Miguel Rodriguez in Miami, you might have to make a few attempts to get the right one though.

Fun fact: Phone books are the reason there are some businesses called AAA. Businesses, such as locksmiths, plumbers, and other rarely used services, would name themselves AAA because it would make their listing first in the type/subject by alphabetical order.

Phone books had your name and phone number. Some had your street address too.
Before that, there were books that even had your occupation.

Random directory example from 1886:
Last name, first name, occupation, street name, number.

1790...

I have never felt so old.

Name, address, and phone number of the account holder used to be published in books that got sent to everyone in the city and also just left lying in boxes that had phones in them if you needed to make a call while you weren't home, because your phone used to be tied to a physical location.
You also used to have to pay extra to make calls to places far away because it used more phone circuits. And by "far away" I mean roughly 50 miles.

It's not the biggest thing in the world, privacy wise, since a surprising amount of information is considered public.
If you know an address, it's pretty much trivial to find the owners name, basic layout of the house, home value, previous owners, utility bill information, tax payments, and so on. I looked up my information and was able to pretty easily get the records for my house, showing I pay my bills on time, when I got my air conditioner replaced and who the contractor who did it was.

As an example, here's the property record for a parking structure owned by the state of Michigan. I chose a public building accessible by anyone and owned by a government to avoid randomly doxing someone, but it's really as easy as searching for public records for some county or city and you'll find something pretty fast.

Charles Bukowski wrote maybe the most beautiful paean to the fact of the telephone book:

https://poemsdaily.livejournal.com/123676.html

Yes. I live in a larger metropolitan area and there were both white and yellow (business) page editions that were 2 1/2 inches thick each.

You could opt out of being in the phone book. I had to do this because a crazy woman who had had a teacher by the same name as me, in the same suburb as me, kept ringing me. First call she said, "Guess who this is?" Dunno. By the tenth call that first day she was yelling down the phone that I was a liar, asking me "Why are you being like this?!?" Because I was never your teacher! No caller id back then, so I had to keep right on answering. One time I picked up and shouted "FUCK OFF!" and yeah it was a work colleague, that was awkward.

Heck, there was even overlap with the internet where you could briefly lookup anyone in any city's white pages listing online for free! People used to sign their Usenet posts with their full name, phone, and mailing address, though. We were really stupid in hindsight, but it was a more innocent time.

I hated how these were delivered to you whether you wanted them or not. So much junk.

They made really great fires though if you tore each page out, crumpled them up and stuffed them between the logs.

Also interesting, I took one about an inch or so thick and shot it point blank with a 12 gauge shotgun and tiny yellow circular confetti came out, which was neat to see.

See the film, Terminator. It's how the machine finds women named Sarah Connor. Or maybe that was Kyle Reese. Either way, it was a major plot point.

Yes

I come from Poland and yes, totally. When I started school, and missed lessons because I was sick or whatever, I could just take the phone book and find the surname of the classmate I wanted to get notes or homework from. If there were a few surnames on the list and I didn't know their father (it was always the man of the house who was listed) first name, I could just go by who appeared to live closest to the school. Or just start calling all the numbers until I got the right one.

TIL we’re at the point where people don’t know what a phone book is. My god I’m old.