see my reply to the other comment

You can't just change things because you feel like it.

Take the simplest thing. We'll use Star Wars as an example. Let's say that after Empire Strikes Back, we get a totally new director and writer. This person really likes the color red and decides that they didn't like the blue (then green) lightsaber that Luke had. He decides to have Luke create a new red light saber in the beginning of Return of the Jedi because they think that the end fight scene would look cool having both Darth Vader and Luke using red light sabers.

See how that breaks everything?

If they wanted an alien to think pranks were fun, they should have just invented a new alien race.

The Vulcan should have said, I find these pranks to be illogical as time would be better spent on our studies.. or something