Standards of beauty never change. For example, in the 19th century few men wore beards or mustaches and all people considered attractive, male and female, had washboard abs.
Every community in the UK outside of London, Manchester, Edinburgh, and Liverpool has at least one resident who’s far too interested in their farm animals.
You can dodge a laser.
Space is incredibly noisy, although it does seem to absent of screams.
You can survive in space if are really good at holding your breath.
Because of the effect of faster than light travel, it actually takes 8 years and/or 8 sequels to complete a five year mission.
Yes, the engines CANNAH take more.
All planets except Earth are numbered because all the good names are taken.
Except Earth, all planets have a single culture, e.g. nazi planets, pleasure planets, etc.
Green skinned alien women are easy, except, of course, the Alien Queen.
To add to Superhal’s list:
Space is dark navy blue, with pretty nebulae most everywhere.
If your FTL drive breaks down, you can “limp” to the nearest planet.
If your ship suffers some major malfunction, you MUST set down on a planet. You know, before you crash.
Despite tremendous advances in multiple scientific fields such as power production, propulsion, weaponry and defense, materials technology, megastructure engineering and strong AI, the basic human condition will be about the same as in the 20th century.
Humans can manually perform many tasks such as piloting better than any machine because of some ineffible quality that can’t be artificially duplicated.
Spacesuits and small craft will always be in danger of running out of air, because it will always be impossible to extract oxygen from carbon dioxide.
And we will still be plagued with male pattern baldness.
And a bunch far too disinterested in dental hygiene.
Similarly, wherever the character happens to be in a city, the story will eventually take him to the Empire State Building, Golden Gate Bridge, Wrigley Field, MIT dome, Space Needle or whathaveyou.
When a movie is set in St. Louis, all characters are inevitably drawn to the Gateway Arch. Furthermore, said characters must approach the Arch from the east (Illinois) and cross over the Mississippi River.
The only time I’ve been through St. Louis it was indeed like I was in a movie about people driving through St. Louis, cause every time I turned around a corner, the Arch was right in my line of sight.
At these places, the seats at the bar are reserved exclusively for single women. The men stand a few feet behind them and take turns approaching them with pickup lines, while the other men watch and comment. These are the rules.
And women never drink beer or even wine. They are required to order something colorful in a martini glass.
And uniform climate: Earth is the only planet out there with climatic variety and a tilted axis.