I said it before, and I’ll say it again: every world needs a moment, a phrase, an image that hits the PC on the head, and reminds him that he’s in Kansas now.
“They do things differently here.”
On the other side of the roleplaying coin, it’s rather rare for the Referee and the Player to come up with something about his homeworld that he’s comfortable with, that would surprise the casual visitor.
It would be worth it, though.
“Woah! I’s completely illegal to drive your own car, where I come from!”
“You let aliens vote?”
“Shouldn’t everyone be carrying a gas mask? I mean, there are clouds in the sky, after all!”
“Why are those people walking with… animals?!?”
“You mean, this is raw, unprocessed food? I’m not touching this!”
<The born spacer running indoors, the first time he feels wind…>
“Everyone is wearing all sorts of clothes! How can you tell someone’s work caste?”
“Why is water falling from the sky?”
“I don’t see any chrome, anywhere! Did you purge all the cyborgs?”
“What in the Imperium is that?”, he said, pointing to…
It’s a big Imperium. Remind your players, every so often.