I mean, all they did was ask if anyone knew how high the highest point in the land would be. It was a pretty innocuous question. I probably would have asked it a similar way.In your case you explained why and didn't expect the world to know what type of info you are looking for and why. Your example is fine and I suspect could also cover how much water is going to be in the toilet bowls. People didn't give me the benefit of that doubt. So fine, but, it seems that being a trivia buff myself, I see no possible time when that information would be useful unless someone is getting ready to rant about how they will show from outside the land. I suspect they will, life goes on!
I've never found "toilet water retention capacity" to be a standard staple in facts and figures the way someone interested in architecture might be able to rattle off the heights of the Eiffel Tower and Empire State Building -- less because they're useful and more because they're simply interesting -- but you do you, I suppose.
Fun Fact: There are 11,324 alucobond triangles on Spaceship Earth. A barely useful bit of information, but sort of fun to know.