"Normal" is a funny word - it's means something that's completely relative to you and your experiences. So for me, I'd ask:

People that went to high school with only 1 floor, did you think that was a bit odd?

People live different lives, normal means different things to different people. Let this be a good lesson to learn: Where you went to school, what your family cooks for dinner, if you drive/walk/take the train to work/school, if you speak one language - none of what you know as "normal" is normal to someone else. More importantly, someone else who experienced different things are not "odd" and those things are also not "odd" - they are just as normal to them as yours are to you. People aren't different, odd, or weird - they're just people. They just had different experiences. Obviously I'm alluding to things, but generally even the most base thoughts like this I like to reinforce that idea.

A better way to ask that may have been upvoted would have been "People who attended high school with 3+ stories, what was that like compared to a 1-story high school?" and give an example of how you only experienced a 1 story.

For me, so many crowded stairwells between classes. You learned what floors had the best bathrooms.