The internet in it's heyday, when it was a genuinely thrilling place to find information, and quite a lot of weirdness, and before it was swamped by corporate interests.

I remember starting out with gopher and a paper print out of 'The big dummies guide to the internet' which was a directory of almost every gopher and ftp site (pre web) along with a description of what you'd find there. Then the web came along and things got really good for a while. Once big corporations got involved it all went down hill.

Not having all the silly teenager / young adult bits of their lives documented in videos for all to see.

Setting up your computer before you go to bed to download a demo for a game that's... 20 MB large! Waking up in the morning to inevitably discover the download failed part way through.

Bugs hitting the front windshield in extraordinary numbers.

Home ownership

The internet being a "place" you would go to and then leave.

That's almost impossible to do now because everything is so linked to being online.

Doing stuff with friends, undocumented.

Not all, but most don't seem to have adventures. When I was a kid I'd go off into the woods and build a den or climb a tree, we once spent a whole week trying to dam a stream, god knows why. None of my friends kids go anywhere by themselves, a lot of them do 'forest school' where they'll be taken by adults to a sanitised woodland and taught how to build a teepee with pre cut wood, and it's just not the same thing.

Getting static shocked by the TV screen.

The App Store not being filled with predatory trash

We used to leave on our bikes for the day (no phones, so basically unreachable). The only rule was you had be back by dinner.

Cleaning out a ball mouse.

My 14 year old son recently picked one up out of this big pile of old computer treasure I was given by a client and said "What's up with this mouse?"

1. Privacy

2. Peace & Quiet

Winter

Accompanying their loved ones to the departure gate at the airport.

Regular police officers not wearing full body armor and tactical gear.

Snow days

Waking up early to catch your cartoons. Or as an adult, having to be at the tv at 7 to watch the new episode. Everything will be streamed, thats fine i guess you wont have to worry about missing it. But it takes away the urgency to keep up.

The nightmare PS2 dirty disc screen, and mainstream multiplayer games without anticheat rootkits

Edit: mainstream

Burning themselves on a light bulb!

Livable planet :)

Using the internet without everyone and their grandmother spying on them and blocking access to stuff the busybodies don't personally like.

Their 60's.

the feeling of not being spied on 24-7

I cannot reply to a previous comment, due to it not federating here, but the children of 2020s will literally be online from day one!

There are countless parents that are posting pictures of their newborns on social media, on Instagram or Facebook, straight to a server in California, so imagine that every single person whose parents are like oh, I don't care about privacy, I got nothing to hide bro will have at least one photo there.

And it's not only that. They'll just never get to experience how life goes with no computer in sight, with no smartphones, not even cellphones at all. No computer, and more importantly, no internet, just cartoons on TV such as Life with Louie or Courage the Cowardly Dog or the Looney Tunes series. And even more importantly, no social media. None at all. Nothing to distract you from actually living.

Finding a nudie mag in the woods

Carrying over heaps of computer equipment (including the mega CRTs before their demise) to your friends house for an all night LAN party that you guys had been prepping for. Then having a blast while parents look at you funny for being into computers.

Oh, and seeing a new BBS at a bus stop that you'd need to go dial into and check out.

Not contacting a person until you meet them again at a location you planned the day before.

Not knowing where you are, locating using literal maps.

It boggles my mind how much safety we have today.

The 1900s

The good side of an album.

And the classic.

Why it's called "Roll down the window".

Being able to chalk off the often embarrassing or cruel lessons of childhood as something personal, rather than something someone saved in video, to hound you with for the rest of your life.

Having your Internet connection drop because someone picked up the phone.

"Smoking" chewing gum cigarettes.

Exploring the internet by going through a physical "100 coolest websites for kids" book.