Addendum

I thought about having it be a status symbol, but the problem with that is soon people with unquestionably high status would write poorly on purpose to show off. We' be back where we are now within a few generations. Here's another suggestion though: Genetic engineering.

Science Fiction Worldbuilding Challenge

Come up with a reason for future people to have generally good handwriting. All I can come up with right now is that it helps with getting through capchas.

Addendum

"We don't have to get a real tree this year. Also I was thinking about going to bed early on the 31st." - future prison inmates

Legal Clarification

It is now illegal to play or listen to Christmas music. That is, in your science fiction setting where future nations try to unify populations flung across planets and space stations by enforcing a universal culture right down to standardizing colors for book covers (military scifi has a diamond pattern).

Culture's Finite Advance

"Why doesn't anyone visit my museum ships?" The man paced around the room, a significant undertaking given its size.
"They're stupid," someone remarked from a couch.
"Why doesn't anyone visit my museum ships? They are an everlasting archive of human achievement. The entire internet year by year preserved in a series of annual superfreighters stationed beyond orbit so that they can also be reached without being touched by any contaminating updates. My private platform offers a free shuttle service, so it can't be the cost, which is what it usually comes down to. Why doesn't anyone visit my museum ships?"
The earlier speaker shrugged. His analysis had not changed, and his employer did not require flattery, obsequiousness, or false hopes.
Therefore it was in all sincerity that another in the room offered a suggestion. "Advertise more?"
"I put it all over every journal of note, every journal not of note, every public libraryr, university, college, community college . . . You did see to that, didn't you?" A thumb rose above the couch. "There, you see?"
"Maybe more, um, popularly oriented advertising? With logos and taglines and celebrities. 'In space, you finally can has cheezburger.' That sort of thing."
"We can try," the pacer allowed.
Within a month, half the population of Earth had migrated to space colonies to shorten the trip to the museum fleet while half the contemporary internet's pages became abandoned for lack of interest.
Finis

Cultural Fragmentation

Soon books will be so optimized that each of them will be readable by only a single person. We will no longer share cultural references. When that day comes, I'm going to tell all you chumps how bad your literary opinions used to be and how glad I am they don't matter any longer.

Genre Family Sizes

We all know fantasy families are too small because it's a pain to come up with names for a bunch of siblings, cousins, etc., but surely science fiction should be dominated by the only child or single sibling absent cloning, right? Look at contemporary fertility. But wait! If you're writing about future people, they must have had future parents and so on down the line, which is to say, they'll belong to cultures which keep those birthrates up. Again, cloning excluded.

History and Mythology Corner

Historically, plenty of people were willing to believe that certain gods and heroes were the same people as other gods and heroes in a different language. Far too willing, really.

April Fool's Day

Don't forget to put dumb traditions in your story. Inside-out clothes day, no hat day, hat day, a day when you're allowed to wear more colors than people of your status typically are, that sort of thing. The important thing is that everyone inside the culture thinks it's normal.

Addendum

And make sure they take their shoes off frequently for cultural reasons! Or never wear them at all! Aaaaaaaahhh!

A Lively Culture

People in your fantasy world probably like poetry, but you don't, so at the end of every chapter write this: "Elsewhere, people were listening to poetry." Problem solved.

Big Worldbuilding Questions

You've got your fantasy country all settled with a name, imports, exports, government type, and everything. You've decided to call it Wipitaria, which I encourage you to rethink, but ignore that and answer me this. Do the people there sit down or recline? Pants or otherwise? How tall are their hats? I won't listen to the answers, though. I only wanted to distract you so I could filch the emerald.

Addendum

A few people, however, should insist that other city stinks and that home city is much better.

Scene Dressing

The easiest way to make your world feel real is for everyone to think some other city is way cooler. We will call this the Paris Method.

The Culture of the New Age

Do people still know Pig Latin? You know, the kids on their Discords and their Pinterests? Or is it deader than actual Latin, which fancy dancies learn, at least a little bit?